Concept of an Integrated Urban Public Transport System Linked to a Railway Network Based on the Principles of a Timed-Transfer Timetable in the City of Prievidza

Abstract

Urban public transport represents a fundamental pillar of a sustainable transport system and a key subsystem within the broader mobility framework in urban environments. This paper focuses on the analysis and optimization of the public transport system in the city of Prievidza and the nearby town of Bojnice in Slovakia, which currently face challenges such as low system attractiveness, operational inefficiency, and weak integration with regional railway transport. This study presents the results of a comprehensive analysis of existing public transport services in Prievidza and Bojnice, including an assessment of passenger flows, line network structure, transfer connections, and operational parameters. Based on the identified deficiencies, a new urban public transport network system is proposed, emphasizing direct links to the railway network. This methodology is developed in the context of an integrated timed-transfer timetable, with defined system time slots at the main transfer hub and a newly designed line network with standardized paths and regular intervals. The proposed system ensures significantly improved connectivity between urban transport and rail services, reduces deadhead kilometres, lowers the number of required vehicles, and leads to a reduction in operational costs by up to 20%. The resulting model serves as a transferable example of efficient service planning in medium-sized cities, with a focus on functional integration, operational efficiency, and sustainable urban development.

1. Introduction

An efficiently functioning urban public transport system represents a key component of systems engineering in transport planning, and simultaneously serves as an indispensable subsystem of a comprehensive urban mobility framework [1,2]. In the context of increasing urbanization, demographic shifts, and environmental challenges, well-designed public transport plays a crucial role not only in reducing traffic congestion, but also as a tool for social inclusion, spatial accessibility, and economic balance. A fundamental element in achieving these goals is the optimal design of a public transport network [3,4], which determines the spatial coverage, connectivity, and transfer relations between different lines and modes [5,6,7]. The network’s structure must ensure effective coverage of residential areas, employment centres, and healthcare and educational facilities, while minimizing transfers and travel times [8]. The design of the public transport system requires the integration of spatial, operational, and passenger demand factors to align service availability with user needs and system capacity [9,10]. Proper network design supports the creation of attractive and competitive public transport services that meet the mobility needs of various population groups [11,12,13]. From the perspective of systems management, urban public transport is an integral part of multimodal transport systems, where the need for optimization, coordination, and decision-making models are growing to enhance the sustainability [14,15] and efficiency [16] of public transport services [17,18,19,20,21].

The Upper Nitra region, specifically the cities of Prievidza and Bojnice, represents an area with strong functional interconnections but a low degree of integration between urban and regional transport. The public transport system in Prievidza does not reflect the principles of an Integrated Transport System (ITS) and shows weak connections to railway transport, which negatively impacts the coordination of services, leads to inefficient line structures, and results in low usage of public transport.

This article presents an innovative systems-based approach to the design of transport services through the application of Integrated Timed-Transfer Timetable (ITTT) principles, supplemented with decision-making models and optimization techniques. The core of this research lies in the development of an optimized public transport network model aimed at improving temporal and spatial connections with regional railway services and enhancing overall system efficiency. The Time-Transfer Timetable, commonly used in railway operations, is adapted in this study to the conditions of a smaller city, introducing a new dimension to its application in integrated transport planning.

This article also provides a methodologically coherent procedure for the optimization and organization of transport services in connection with the railway network. The results have practical implications, enabling improved transfer connections between trains and urban public transport, increased system efficiency, reduced dependency on individual car use, and, ultimately, an improved quality of life for residents. Developing a new public transport system capable of operating effectively within an ITS environment requires thorough knowledge of the territory where transport services are to be organized, as well as a detailed understanding of the current state of the system. This includes not only line design, but also stop accessibility, ordered transport performance volumes, travel flows, and various other issues currently affecting the public transport system.

Given that, in February 2025, the City of Trenčín and the Trenčín Region joined what is now the Integrated Transport System of the Žilina and Trenčín Regions, there is a strong presumption that further integration of various transport systems into a unified ITS will occur in the coming years. As the boundaries between urban and regional transport are increasingly blurred within ITS structures, proposed solutions will be created and evaluated in a broader context.

The innovative nature of this research lies primarily in the application of Integrated Timed-Transfer Timetable principles to the design of public transport lines in the context of a medium-sized Slovakian city with a strong functional link to regional rail services. Unlike most existing studies [12,22,23] that focus either on large metropolitan systems or on theoretical modelling in isolated transport modules, this research integrates multiple decision-making dimensions—spatial, temporal, operational, and organizational—into a coherent and practically applicable proposal.

Another innovative aspect of this research is our emphasis on low-cost optimization without the need for additional investments in infrastructure or rolling stock, which is a highly relevant approach for smaller cities and regions with limited budgets. This research also expands the ITTT concept beyond the railway sector and demonstrates its applicability in urban transport, setting a precedent for the implementation of integrated scheduling in other Slovakian cities outside of major metropolitan areas. The benefits of this research include the ease of implementation of the proposed solutions, reduction in inefficient transfer times, improved accessibility of public transport, higher operational reliability, and the potential to increase the modal split in favour of public transport. In addition to its practical impact, this research also contributes methodologically by offering a comprehensive design procedure that can be replicated and adapted to various regional and organizational conditions.

The structure of this article provides a comprehensive perspective on the design of an optimized urban public transport system, with an emphasis on its integration into the broader transportation network. The Introduction section clarifies the importance of integrated public transport services in medium-sized cities within the context of systems engineering and increasing demands for sustainability and efficiency.

The Literature Review summarizes current findings in the areas of line network design, multimodal coordination, and the application of integrated timetables, with a particular focus on research related to integrated transport systems and decision-making models in transport.

The Methodology section introduces a systematic methodological framework based on the practical need to optimize transport service organization, emphasizing the efficiency, connection synchronization, and simplification of timetables. The Methodology section includes a sequential description of steps such as passenger flow identification, line design, and the harmonization of timetable nodes.

The Research Background section provides an analytical overview of the current state of urban public transport in Prievidza and Bojnice, identifies the key problems of the existing system, and defines the spatial-temporal and functional relations with regional rail and bus transport. It also sets out the decision-making criteria that form the basis of the design phase.

The Results section presents the proposed new urban transport network and specific lines for the cities of Prievidza and Bojnice, including their integration with rail transport. The results are illustrated with maps, tables, and detailed descriptions of individual lines.

The Discussion section compares the parameters of the original and proposed systems, with an emphasis on improved connectivity, time reliability, and operational efficiency. It also evaluates the potential impact on modal split and the reduction in individual car use.

Finally, the Conclusions section summarizes the benefits of the proposed solution from the perspective of transport system management, and offers recommendations for further research and implementation within integrated transport systems.

2. Literature Review

The effective planning of urban public transport and its integration with railway services represent key instruments for the development of sustainable mobility in urban and suburban areas. The importance of integrating transport systems has grown significantly over recent decades in the context of increasing demands for ecological sustainability, accessibility, and efficiency [24,25]. This section presents the theoretical and methodological approaches that provide a framework for designing transport services in the cities of Prievidza and Bojnice.

2.1. Integrated Transport Systems

Current research in public transport planning and optimization focuses on the integration of transport systems [26], advanced modelling approaches [27], and the use of simulation tools to support decision-making. A study by [28] offers a comprehensive overview of urban public transport integration practices in global metropolitan areas, identifying key benefits, such as improved connectivity and travel comfort, alongside challenges related to fare, timetable, and spatial coordination. The concept of an Integrated Transport System reflects the need for a unified, effectively interconnected public transport network that combines rail, bus, and urban transit modes into a fare- and organizationally integrated structure. The author of another study [29] defines the core elements of ITS as a common fare policy, harmonized timetables, transfer hubs, and an integrated information system. ITS enhances travel comfort and increases the efficiency of public expenditure. Examples of successful integration include regions such as Verkehrsverbund Rhein-Ruhr (Germany), Île-de-France Mobilités (France), and the JR system (Japan) [30], where emphasis on modal synchronization significantly contributed to the attractiveness of public transport [31]. Comparative lessons from these international cases can provide important insights for smaller cities such as Prievidza. The German Verkehrsverbund Rhein-Ruhr demonstrates the importance of integrated fare systems and coordinated scheduling even across multiple operators and administrative boundaries. Île-de-France Mobilités highlights the role of centralized network governance, information systems, and real-time data integration in increasing passenger convenience. The Japanese JR system shows how strict adherence to synchronized transfer timetables can achieve high reliability even in networks with complex interconnections. While these systems operate at a larger scale, key principles, such as coordinated headways, stabilized transfer nodes, passenger-oriented timetable design, and the gradual integration of regional and urban services, remain highly transferable to smaller cities seeking low-cost but effective improvements. The proposed Prievidza model adopts several of these core principles while adapting them to local operational and financial constraints.

2.2. Timed-Transfer Timetable and Its Benefits

A Timed-Transfer Timetable (TTT), sometimes referred to as a Integrated Timed-Transfer Timetable, is a public transport scheduling principle in which services on multiple routes are synchronized to allow for guaranteed connections at designated transfer hubs at specific recurring time intervals. The concept seeks to optimize passenger convenience by minimizing transfer waiting times while maintaining regular and easily understandable schedules throughout the day [32,33]. Multiple studies have analyzed the design, implementation, and operational benefits of TTT systems across different public transport contexts. The principle of a regular cyclic timetable significantly improves memorability and allows for optimized transfers [34]. The authors of [35] emphasized that TTT provides substantial advantages in regional and suburban railway systems with lower-frequency operations, where maximizing connectivity becomes more important than pure frequency increases. The study by [36] presented modelling approaches for synchronization in urban bus networks, showing that timed-transfers can significantly reduce generalized travel time for passengers in medium-sized urban areas. In the article by [37], the authors analyzed the impact of timetable coordination in the Stockholm suburban railway network, demonstrating increased system reliability and passenger satisfaction. The author of [38] provided mathematical models for optimizing periodic timetables and their synchronization properties, underlining the computational complexity of TTT design in larger networks. The study by [39] investigated the Swiss national TTT model (Taktfahrplan), highlighting its success in coordinating regional, suburban, and long-distance services through systematically arranged transfer hubs. The authors of [40] extended TTT principles to high-density multimodal networks, discussing their integration with real-time control systems.

2.3. Coordination of Rail and Urban Transport

Effective coordination between rail and urban transport is crucial for achieving a high level of intermodality. The study by [41] analyzed the impact of public transport coordination on passenger satisfaction. Their findings show that optimizing transfers and harmonizing timetables can significantly enhance user satisfaction and public transport efficiency. The authors of [42] found that transfers represent a considerable cost for passengers that are unevenly distributed across stations and platforms. They emphasized the economic implications of waiting times during transfers. The study highlights that improving transfer nodes and better understanding passenger behaviour during transfers can greatly increase the attractiveness of public transport. The importance of rail and bus coordination in Slovakian regional contexts is demonstrated, for example, in the study by [43], which analyzed transfer synchronization in the Zvolen–Banská Bystrica corridor.

2.4. Line Planning and Network Design and Quality

International research offers many applicable approaches. In the study by [44], the authors proposed a methodology for ITS design in Poland, with a focus on regional integration. In the Central European context, the study by [45] focused on the design of backbone lines in the Upper Šariš region, while the study by [46] analyzed the public transport network in the Pardubice agglomeration. The article by [47] examined a specific rail segment from the perspective of transfer options. The authors of [48] presented participatory public transport planning using the example of the Croatian ITS. The study by [49] analyzed line planning in the Prešov region using the AHP method. The authors of [50] focused on designing urban transport systems, with an emphasis on their environmental aspects. More advanced network designs considering stochastic passenger behaviour were explored by [51], who combined multi-criteria decision-making with behavioural models. A significant contribution to public transport management is also provided by multi-agent systems. In the study by [52], the authors demonstrated the use of autonomous agents in APTS and ITS for real-time adaptive control. Another study focuses on public transport route planning includes [53]. The studies by [54,55] focus on the connection quality of the transport network.

In contrast to much of the existing research, which focuses either on large metropolitan systems with complex infrastructures or on theoretical simulation-based optimization models, this study addresses the practical challenges of optimizing urban public transport systems in small-to-medium-sized cities with limited resources. While previous studies have analyzed integrated timetables, multimodal coordination, and network design algorithms, there remains a research gap in the operational application of integrated timed-transfer principles within smaller regional contexts, where railway connections play a significant role but full-scale multimodal integration is often lacking.

This research contributes to filling this gap by adapting the Integrated Timed-Transfer Timetable methodology to a real-world mid-sized Slovakian city (Prievidza–Bojnice) with strong spatial–functional interconnections but weak existing coordination, proposing a systematic method for synchronizing urban bus services with railway operations based on both analytical transfer matrices and operational feasibility, providing a low-cost optimization framework that does not require major infrastructure investments or high-frequency services, but still offers significant gains in transfer reliability, network simplicity, and operational efficiency, offering a transferable design procedure that may serve as a practical planning tool for similar urban–regional environments across Central Europe. This study introduces a replicable model that addresses both academic and practical gaps in the coordination of public transport services in regional urban areas.

3. Methodology

The methodology for designing transport services (Figure 1) is based on the practical need to optimize public transport provision in the cities of Prievidza and Bojnice, with the aim of increasing the attractiveness of urban public transport and ensuring its integration with regional rail services. This research focuses on improving transfer connections, service regularity, and the functional logic of lines within the framework of an Integrated Transport System. Our goal is to design a simplified, comprehensible, and cyclically structured network that reflects actual transport demand while adhering to the principles of the railway timed-transfer timetable. The methodology enables verification of whether the proposed network meets the objectives of integrated transport service provision and complies with the requirements of timed planning in public transport.

• Description of the Methodology

Data Collection and Analytical Framework—The foundation of the methodological approach was a comprehensive data collection process concerning the current state of the transport network in the cities of Prievidza and Bojnice. Particular attention was given to the existing transport supply, including timetables, lines, and service intervals. A key aspect involved identifying major origin and destination points for passenger flows, as well as assessing the connectivity between urban public transport and railway services. As part of the planning process, the locations and spatial accessibility of individual stops were analyzed, with an emphasis on existing lines and time-based connections between urban public transport and train services. A combination of qualitative and quantitative analytical methods was employed to create mapping outputs, transfer connection matrices, and accessibility calculations based on time and distance data. The primary data collection involved semi-structured interviews with 42 public transport users conducted over a two-month period (March–April 2024), covering both regular commuters and occasional passengers. Given the objective of the optimization design and the characteristics of the territory, the sample size is considered sufficient to identify the main travel patterns and critical issues within the existing network. The respondents were selected to represent various user categories, including employees commuting to industrial zones, students, senior citizens, and spa visitors. To capture variability related to seasonal fluctuations, the data collection period intentionally included the early phase of the spa season in Bojnice, which typically sees a rise in passenger volumes due to spa-related tourism. Publicly available data sources Centralized timetable database of Slovakia (CP.sk), timetables of the Železničná spoločnosť Slovensko (ZSSK, Bratislava, Slovakia), and Google Maps, complemented the field data by providing schedule accuracy, stop accessibility, and travel time data for both peak and off-peak periods. This combined approach ensured a comprehensive understanding of typical demand profiles while partially accounting for seasonal effects.

Stages of Line Network Design—The process of designing the urban public transport line network consists of several logically organized steps that follow the principles of spatial planning, transport engineering, and system integration. Figure 2 illustrates the stages of line network design within the urban transport system.

In the initial phase, a spatial analysis was conducted to identify major generators and attractors of transport demand, including residential, educational, healthcare, recreational, and administrative facilities. This was followed by a functional division of the urbanized area into transport zones based on the predominant types of activity and expected travel patterns. A critical stage was the analysis of origin and destination areas of mobility, aiming to understand the dominant travel flows within the urban system. The methodological framework also included an assessment of connections and integration with the higher-level transport system, particularly regional railway transport, in the context of incorporating it into the urban network. The final step was the identification of potential transfer hubs and transport centres that could serve as multimodal interchange points within the planned system.

Application of Integrated Timed-Transfer Timetable Principles—In the design of the line network, the principles of the Integrated Timed-Transfer Timetable were applied, characterized by regular departures at fixed intervals—typically every 30 min. The system is designed so that transfer hubs provide guaranteed connections through synchronization with train arrivals. Simplicity of the network was also considered; a key objective was to reduce the number of lines while maintaining service coverage of all major areas. System stability was ensured through a stabilized vehicle circulation system, with vehicles deployed in a periodic operational regime. The resulting timetable was designed in the form of a cyclic matrix with a main axis at 00/30 min and additional connections at 15/45 min. When compiling the timetable, actual train arrival and departure times were considered, along with the need to establish bidirectional transfer connectivity for passengers.

Line and Vehicle Circulation Design—Based on the analytical phase and ITTT principles, three core public transport lines were proposed to connect key city areas with major transfer points:

• Line A connects the northern part of the city with the railway station, the hospital, and the city of Bojnice, thus linking residential neighbourhoods with healthcare and recreational centres.
• Line B provides service between the Žabník district, the city centre, the hospital, and the Nové Mesto housing estate.
• Line C was designed as a circulatory line synchronized with train arrivals, thereby strengthening intra-urban connectivity and transfer functionality within the system.

For each line, a timetable based on ITTT principles was developed (for example, 05:00, 05:30, and 06:00), along with a transfer matrix between public transport and railway connections. The vehicle circulation design aimed to minimize the need for reserve capacity and ensure efficient vehicle deployment. Circulation was modelled to minimize idle time and achieve balanced vehicle utilization throughout the day.

• Visualization and Technical Tools

The following tools were used in the development of the proposed design:

• A timetable diagram to illustrate the lines and their connections to rail services;
• Custom graphical schematics for comparing the current and proposed states of the network.

• Indicators for Line Design

The following indicators were used in the design and evaluation of the network:

• Vehicle circulation time:

$$C_o=n\times T$$

(1)

where

C_o—circulation time of a single vehicle (minutes);

T—line headway (for example, 30 min);

n—number of headways covered by a single vehicle.

• Transfer Synchronization Index (TSI):

$$TSI={\displaystyle \frac{P_z}{P_t}}\times 100\%$$

(2)

where

P_z—number of guaranteed transfers (for example urban public transport → train)

P_t—total number of analyzed transfers.

• Transport Network Coverage:

$$C={\displaystyle \frac{{\sum }_{i=1}^n{w}_i\times x_i}{{\sum }_{i=1}^n{w}_i}}\times 100\%$$

(3)

where

W_i—population count or importance of area i;

X_i—1 if area i is served by public transport, 0 otherwise;

n—total number of territorial units.

• Network Complexity Indicator:

$$S={\displaystyle \frac{L}{Z}}$$

(4)

where

L—number of public transport lines;

Z—number of stops in the system.

• Average Number of Transfers per Trip:
• Used to assess passenger comfort and the availability of direct connections.

$$P_{avg}={\displaystyle \frac{{\sum }_{i=1}^n{p}_i}{n}}$$

(5)

where

p_i—number of transfers on the i-th trip (obtained from travel chains);

n—number of analyzed trips.

• Network Efficiency Index (Travel Time Ratio—TTR):
• Helps assess the competitiveness of public transport compared to private car travel.

$$TTR={\displaystyle \frac{T_{publictransport}}{T_{car}}}$$

(6)

where

T_{public transport}—average travel time by public transport;

T_car—average travel time by car for the same line segment.

• Load Factor:
• Indicates the efficiency of vehicle utilization on individual lines.

$$LF={\displaystyle \frac{P_{obs}}{C_{vehicle}}}\times 100\%$$

(7)

where

P_obs—average number of passengers per service;

C_vehicle—capacity of the given vehicle.

• Train and Public Transport Time Synchronization Index (Generalized Waiting Time Index):

$$GWT={\displaystyle \frac{1}{n}}{\sum }_{i=1}^n\left(t_{wait,i}-t_{ideal}\right)$$

(8)

where

t_wait,i—actual waiting time for transfer i;

t_ideal—target (acceptable) transfer time (for example, 5 min);

n—number of transfers.

• Evaluation Criteria for the Proposed Network

The network design was evaluated based on the following criteria:

• Extent of territorial coverage;
• Temporal reliability of transfers;
• Clarity and efficiency of the network;
• Improved connectivity to railway transport;
• Expected reduction in transfer times and increase in direct connections.

Table 1. Summary of symbols and notations.

Symbol	Description
Co	Circulation time of a single vehicle (minutes)
T	Line headway (minutes)
n	Number of headways covered by a single vehicle
Pz	Number of guaranteed transfers
Pt	Total number of analyzed transfers
Wi	Population counts or importance of area i
Xi	Service availability for area i (1 = served, 0 = not served)
L	Number of public transport lines
Z	Number of stops in the system
pi	Number of transfers on the i-th trip
Tpublic transport	Average travel time by public transport
Tcar	Average travel time by car
Pobs	Average number of passengers per service
Cvehicle	Vehicle capacity
twait,i	Actual waiting time for transfer i
tideal	Target (acceptable) transfer time

provides a comprehensive summary of all symbols applied in the presented mathematical formulas.

The set of indicators applied in the evaluation of the proposed network was based on established methodologies from the public transport planning literature, as well as on adaptations derived from practical system design experience in Central European contexts. Key methodological sources include references [56,57,58], who extensively describe network structure evaluation, transfer coordination, and operational efficiency metrics. While some indicators, such as the Network Complexity Indicator and Transfer Synchronization Index, were adapted to reflect the specific characteristics of the studied city and integrated timetable system, their formulation remains consistent with internationally recognized evaluation frameworks.

4. Research Background

Urban public transport in Prievidza has long constituted an integrated network of transport lines that serve two territorially and functionally interconnected settlements: the city of Prievidza and the neighbouring spa town of Bojnice. The public transport services are commissioned by both municipalities, which jointly finance the individual lines based on a valid public service contract and predefined rules [59]. Given the strong social, economic, and spatial ties between the two cities, this represents a pragmatic and efficient solution. Urban public transport services in the city of Prievidza are operated by the transport company Slovenská autobuová doprava Prievidza, a.s. (SAD Prievidza, a.s.—bus operator), with the system based exclusively on bus transport. Urban public transport faces competition from private modes of transport and, to a certain extent, from regional bus transport, which, however, is currently neither operationally nor fare-integrated, and represents an independent alternative for passengers travelling within the city. A major issue in the current system is the weak connectivity between urban public transport and railway transport, as well as the absence of a timed-transfer system in regional bus services [60,61]. The existing supply-based timetable model of regional bus transport reduces the overall attractiveness of public transport compared to individual automobile travel.

The introduction of the so-called “revolutionary timetable” during the 2022/2023 timetable year brought about the significant reorganization of rail services; the Prievidza junction is currently served by three lines operating at regular hourly or bi-hourly intervals. The timed-transfer hub position at xx:00 greatly supports the development of connections to urban public transport; however, only three bus lines currently operate on a synchronized timetable: lines 40, 44, and 51. In terms of service coverage, the urban public transport system in Prievidza and Bojnice comprises 12 lines, operated predominantly by second-hand vehicles. Among standard buses, the most frequently used models are SOR BNG 12 and SOR NB 12, while Solaris Urbino 10.5 is commonly deployed in the midibus category. Most of the fleet is powered by Compressed Natural Gas (CNG).

4.1. Current Status of the Urban Public Transport Network

The urban public transport system in the city of Prievidza is exclusively operated by SAD Prievidza, a.s. The network includes multiple bus routes, serving both the city core and peripheral areas, including connections to the neighbouring spa town of Bojnice. The operator utilizes a fleet of Compressed Natural Gas (CNG) vehicles, contributing to a lower environmental impact compared to diesel-powered fleets.

The operational parameters of the current bus network are summarized in

Table 2. Operational parameters of existing bus lines in Prievidza.

Line	Route Description	Headway (min)	First Departure	Last Departure	Operator	Vehicle Type
2	Bus station—Cesta poľnohospodárov—Vápenická	30	05:00	22:00	SAD Prievidza	CNG bus
3	(GeWiS)—Pod skalou—Bus station—Sídlisko Píly—Bojnice kúpele	20	05:10	21:45	SAD Prievidza	CNG bus
7	Bojnice Dubnica—Bojnice kúpele	30	05:20	21:30	SAD Prievidza	CNG bus
8	Bus station—Pod skalou—M. Lehôtka—Hradec—V. Lehôtka—Pod skalou—Bus station	60	05:30	20:00	SAD Prievidza	CNG bus
10	(SAD)—Bus station—Zapotôčky—Sídlisko Píly	20	05:00	22:15	SAD Prievidza	CNG bus
15	Gymnázium—Kopanice—Bus station—Zapotôčky—Bojnice Dubnica	30	05:15	21:45	SAD Prievidza	CNG bus
40	Sídlisko Píly—Bus station—Necpaly—Kopanice—Centrum—Pod skalou (GeWiS)	30	05:00	22:00	SAD Prievidza	CNG bus
44	Bus station—Necpaly—Kopanice—Bus station	60	05:20	20:30	SAD Prievidza	CNG bus
50	SAD—Kopanice—Necpaly—Zapotôčky—Bojnice—Sídlisko Píly—Bus station—SAD	30	05:10	21:50	SAD Prievidza	CNG bus
51	SAD—Bus station—Sídlisko Píly—Bojnice—Zapotôčky—Necpaly—Kopanice—SAD	30	05:05	22:00	SAD Prievidza	CNG bus
83	Brose—Bus station—Kopanice—Necpaly—Zapotôčky—Zimný štadión	30	05:15	21:00	SAD Prievidza	CNG bus
90	(GeWiS)—Pod skalou—Bus station—Zapotôčky/Sídlisko Píly—Bojnice Dubnica	30	05:00	22:00	SAD Prievidza	CNG bus

The table provides an overview of the primary bus lines, including key route segments, service headways, first and last departures, and vehicle types.

The network primarily operates during standard daytime hours, with limited frequency reductions in the evening and during weekends. The network structure is characterized by a combination of radial, circular, and tangential route patterns, serving key functional zones such as residential districts, industrial parks, educational institutions, healthcare facilities, and tourist destinations—notably, the Bojnice spa complex. The current urban public transport network scheme in Prievidza and Bojnice is illustrated in Figure 3.

4.2. Analysis of Existing Network Problems

Despite the relatively wide coverage of the public transport network, multiple deficiencies have been identified based on field observations, service schedule analysis, and interviews with public transport users. The key problems are summarized in

Table 3. Identified deficiencies in the existing urban public transport network.

Identified Problem	Description	Impact on Service Quality
Line Duplication	Multiple lines partially overlap along the main corridors between the city centre and Bojnice	Operational inefficiency, confusing route structures for passengers
Poor Railway Connectivity	Lack of systematic coordination with regional railway services (lines R7, S7, S51)	Extended transfer times, limited intermodality
Uneven Headways	Different lines operate with non-harmonized headways, varying from 15 to 30 min	Difficulties for passengers to plan multimodal trips
Peripheral Area Coverage	Limited service to suburban neighbourhoods and new residential developments	Accessibility gaps for certain population segments
Transfer Reliability	Inconsistent transfer times often exceeding recommended thresholds (10 min and more)	Reduced network attractiveness, increased perceived travel times
Peak Period Overcrowding	Overloading of certain services during peak commuting periods	Passenger discomfort, service quality decline
Low Evening and Weekend Frequencies	Substantially reduced service levels after 7:00 p.m. and during weekends	Reduced usability for non-commuting trips

.

These deficiencies negatively affect the attractiveness, competitiveness, and operational efficiency of the public transport network, particularly in the context of multimodal integration and transfer synchronization.

The current urban public transport system in Prievidza faces typical challenges that are characteristic of many smaller Slovak cities. Among the most notable deficiencies are inefficient vehicle deployment (including a high share of non-revenue runs), inadequately set travel times, poor passenger information, and an inefficient boarding system where every passenger is checked exclusively at the front door. One of the key issues is the excessive number of repositioning runs between individual services, which generates a high proportion of dead kilometres. Due to the unsystematic structure of the timetable and the non-linear routing of services, situations arise in which layovers become excessive, often exceeding the legally defined break periods. Moreover, driver changes are regularly carried out at the depot, resulting in the underutilization of vehicles during peak hours—precisely when they are most needed.

Currently, the lines are not organized based on regular patterns with fixed intervals, but rather as individually timetabled services with varied routing and no unified headway. This system significantly complicates the creation of optimized vehicle rotations. The Prievidza urban public transport timetables lack standardized travel times for identical segments, and do not define time profiles. There is also no consistent chronometric coordination for adjacent services operating on the same line. Services with overestimated travel times often depart late, but arrive at their final stop early, which impairs transfer reliability and distorts the actual perception of system reliability. Figure 4 presents the delay pattern of a selected service on line 40, clearly illustrating the discrepancy between the timetabled time and actual travel time.

Throughout the entire public transport network in Prievidza and Bojnice, a front-door boarding system is implemented. Every passenger is required to either pay the fare or validate their transport card—even in the case of prepaid tickets, which generate a printed zero-value receipt. While this system ensures accurate passenger tracking and fare control, it causes significant delays during peak hours, which may negatively impact the overall attractiveness of public transport. On less-frequented services outside of peak periods or during non-working days, its impact is marginal.

Another issue is the high number of low-frequency lines, which has led to the creation of line bundles to ensure more attractive intervals in major corridors. However, this approach results in a highly interdependent network, where even minor adjustments to one line can negatively impact the timetables of several others. In practice, this means that changes in one part of the network may have unintended consequences in other areas of the city.

4.3. Determining Criteria for the New Line Network System

The design of a new system for Public Passenger Transport (PPT) must be based on a thorough analysis of qualitative indicators as well as legislative requirements. In addition to qualitative criteria, the proposals must comply with legislative standards, primarily defined by Decree No. 269/2024 Coll. [62]. The general standards specify the maximum allowable number of transfers, acceptable transfer time duration, service intervals, stop service frequency, and the required daily service span [63]. A key requirement is the definition of a base interval, with all other intervals needing to be integer even-numbered divisors of the base interval. The standard required operating hours for lines are from 5:00 to 23:00.

• Fundamental Principles of Urban Public Transport Networks

The increasing number of registered private vehicles, the growing share of individual transport, and the resulting negative effects on traffic flow and ecological sustainability in urban environments highlight the need to promote public transport as the preferred mode of travel.

The quality of public transport directly influences passenger demand. The key attributes of a high-quality and modern urban public transport system include the following [64,65]:

• Network density—determined by settlement patterns and urban structure;
• Stop accessibility—both spatial and temporal accessibility, including the quality of access lines;
• Service frequency—higher frequency increases flexibility and competitiveness;
• Travel speed—influenced by transfers, headways, and traffic flow;
• Total journey time—including walking and waiting times;
• Fare level—appropriate pricing policy and discount schemes;
• Ease of fare collection—modern technologies, card payments, mobile applications;
• Service regularity—timed-transfer operation and easy-to-remember timetables;
• Passenger information—availability of information both online and at stops.

• Typology of Urban Public Transport Network Systems

When designing a new public transport service system, it is essential to find a solution that ensures a high level of accessibility and reliability while optimizing operational costs. In the process of network reorganization, it is necessary to respect the following principles [66]:

• Maintaining a stop’s accessibility when rerouting lines so that passengers do not perceive the new system as a regression.
• Maximizing compatibility between the urban public transport network and regional services in the absence of full integration within an Integrated Transport System.
• Efficient use of available resources—either by covering a larger area with the same capacity or by reducing the number of vehicles and personnel required.

In the case of the Prievidza and Bojnice area, the natural core is the central zone of the city of Prievidza, surrounded by residential and industrial areas. Except for the peripheral location of Bojnice, the territory forms a compact and functionally cohesive area suitable for timed-transfer network organization. A key factor in improving the quality of transport service provision is the integration of urban public transport into an ITS. In a fully integrated environment, fares, services, and timetables are unified across urban, regional, and railway transport [67,68]. A higher level of integration enhances the attractiveness of public transport and stimulates demand [69]. The design of an optimal service volume must reflect actual temporal demand profiles. Figure 5 illustrates the number of passengers transported at various times of day. The results indicate a somewhat non-standard passenger behaviour pattern. The morning peak is concentrated between 5:00 and 8:00, primarily due to shifts starting at 6:00. This is followed by a pronounced off-peak period, during which the number of boardings may, in some cases, exceed peak hour values. The afternoon peak is concentrated in a short window from 13:00 to approximately 16:00, after which there is a sharp decline. After 7:00 p.m., the number of boardings drops to between 0 and 60 passengers per hour, as shown in Figure 5.

4.4. Temporal and Spatial Connectivity with Railway Transport

Prievidza railway station is equipped with level-access platforms, which allow for barrier-free transfers between rail services and urban public transport stops. Based on measurements conducted during the development of the Public Transport Service Plan, an indicative transfer time was established. The walking time from the farthest point of the platform to the most distant urban public transport stop is approximately 5 min at a slow walking pace. The shortest possible transfer from the platform to the nearest urban public transport stop was measured at 1 min and 7 s. For the purposes of further analysis, a standard minimum transfer time of 5 min was adopted.

The connectivity analysis was based on the classification of urban public transport services according to railway lines, examining the feasibility of transfers at train arrivals and departures. The methodological approach was derived from the procedures applied in the development of the Public Transport Service Plan. In this study, the evaluation of transfer success focuses primarily on the synchronization quality between connecting services. A transfer is considered “successful” when the scheduled waiting time at the transfer node falls within a target transfer window of 5–15 min. This interval is consistent with passenger expectations for convenient and time-efficient transfers in urban–regional public transport systems. Transfers falling outside this window are classified as “unsuccessful transfers” for the purposes of synchronization evaluation, recognizing that, technically, alternative connections may still exist for passengers willing to wait longer. However, such extended waiting times are assumed to significantly reduce overall passenger satisfaction, perceived service quality, and network competitiveness. Therefore, the applied definition reflects transfer attractiveness rather than absolute physical transfer possibility. This approach allows for quantifying and comparing the efficiency of network designs under varying levels of synchronization.

In cases where multiple potential connections were available, only the most suitable one was included in the analysis. For the purposes of the following connectivity analysis, railway train services are categorized using their standard operational designations: “R” denotes express services (fast trains) and “Os” denotes regional passenger trains (local stopping services). This classification is consistently applied throughout the subsequent tables and analyses.

• Line R7 (Prievidza–Bratislava)

The tabular analysis (

Table 4. Connections between line R7 and Prievidza urban public transport services on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
R 741	7:50	7:53 (40)	7:53 (40)	7:51 (51)	8:05 (3)	8:05 (3)
R 743	9:50	9:53 (40)	9:53 (40)	10:00 (15)	10:04 (3)	10:00 (15)
R 745	11:50	11:53 (40)	11:53 (40)	12:04 (15)	11:57 (51)	11:57 (51)
R 747	13:50	13:53 (40)	13:53 (40)	13:57 (10)	13:57 (10)	13:52 (51)
R 749	15:50	15:54 (40)	15:54 (40)	16:02 (10)	16:02 (10)	16:04 (15)
R 751	17:50	17:53 (40)	17:53 (40)	x	17:52 (51)	17:52 (51)
R 753	19:50	19:55 (40)	19:55 (40)	20:10 (10)	19:57 (51)	19:57 (51)
Os 755	21:52	22:22 (83)	22:22 (83)	22:15 (10)	22:07 (51)	22:07 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 740	4:10	3:58 (44)	3:58 (44)	4:00 (10)	4:00 (10)	x
R 742	6:16	6:11 (15)	6:09 (40)	6:04 (10)	6:04 (10)	5:59 (15)
R 744	8:16	8:10 (40)	8:10 (40)	8:10 (10)	8:08 (50)	8:08 (50)
R 746	10:16	10:10 (40)	10:10 (40)	10:13 (90)	10:04 (50)	12:04 (50)
R 748	12:16	12:04 (15)	12:10 (40)	12:17 (10)	12:04 (50)	12:04 (50)
R 750	14:16	14:07 (15)	14:15 (40)	13:57 (10)	14:05 (3)	14:05 (3)
R 752	16:16	16:10 (40)	16:10 (40)	15:56 (90)	15:59 (50)	15:59 (50)
R 754	18:16	18:09 (40)	18:09 (40)	18:05 (10)	18:03 (50)	18:03 (50)

and

Table 5. Connections between line R7 and Prievidza urban public transport services on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
R 741	7:50	x	x	7:47 (10)	8:05 (3)	8:05 (3)
R 743	9:50	9:58 (40)	9:58 (40)	10:17 (10)	9:52 (51)	9:52 (51)
R 745	11:50	x	x	12:02 (10)	11:57 (51)	11:57 (51)
R 747	13:50	13:54 (40)	13:54 (40)	x	13:52 (51)	13:52 (51)
R 749	15:50	x	x	16:17 (10)	15:52 (51)	15:52 (51)
R 751	17:50	17:53 (40)	17:53 (40)	x	17:52 (51)	17:52 (51)
R 753	19:50	x	x	20:10 (10)	19:57 (51)	19:57 (51)
Os 755	21:52	x	x	x	22:07 (51)	22:07 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 740	4:10	x	x	x	x	x
R 742	6:16	x	x	x	5:59 (50)	5:59 (50)
R 744	8:16	8:10 (40)	8:10 (40)	8:10 (10)	8:10 (10)	8:04 (50)
R 746	10:16	x	x	9:49 (10)	10:02 (50)	10:02 (50)
R 748	12:16	12:10 (40)	12:10 (40)	x	12:04 (50)	12:04 (50)
R 750	14:16	x	x	14:18 (90)	14:04 (50)	14:04 (50)
R 752	16:16	16:10 (40)	16:10 (40)	x	x	x
R 754	18:16	x	x	18:05 (10)	18:05 (10)	18:16 (90)

) indicates that suitable connections are available primarily for the residential areas of Píly and Bojnice. Residents of Kopanice and Zapotôčky have limited access to connections—either the transfers are too tight, or they are completely missing. The situation is particularly unfavourable on non-working days for line 40, which operates at 40 min intervals. The symbol “x” indicates that no connection exists in the respective direction.

Table 6. Summary of transfer connections between trains and urban public transport on railway line R7.

Train	Train Arrival Time	Bus Departure Time	Bus Line	Direction	Waiting Time (min)	Transfer Successful
R 741	07:50	07:53	40	Kopanice	3	Yes
R 741	07:50	07:53	40	Necpaly	3	Yes
R 741	07:50	07:51	51	Zapotôčky	1	Yes
R 741	07:50	08:05	3	Píly	15	Yes
R 741	07:50	08:05	3	Bojnice	15	Yes
R 743	09:50	09:53	40	Kopanice	3	Yes
R 743	09:50	09:53	40	Necpaly	3	Yes
R 743	09:50	10:00	15	Zapotôčky	10	Yes
R 743	09:50	10:04	3	Píly	14	Yes
R 743	09:50	10:00	15	Bojnice	10	Yes
R 745	11:50	11:53	40	Kopanice	3	Yes
R 745	11:50	11:53	40	Necpaly	3	Yes
R 745	11:50	12:04	15	Zapotôčky	14	Yes
R 745	11:50	11:57	51	Píly	7	Yes
R 745	11:50	11:57	51	Bojnice	7	Yes
R 747	13:50	13:53	40	Kopanice	3	Yes
R 747	13:50	13:53	40	Necpaly	3	Yes
R 747	13:50	13:57	10	Zapotôčky	7	Yes
R 747	13:50	13:57	10	Píly	7	Yes
R 747	13:50	13:52	51	Bojnice	2	Yes
R 749	15:50	15:54	40	Kopanice	4	Yes
R 749	15:50	15:54	40	Necpaly	4	Yes
R 749	15:50	16:02	10	Zapotôčky	12	Yes
R 749	15:50	16:02	10	Píly	12	Yes
R 749	15:50	16:04	15	Bojnice	14	Yes
R 751	17:50	17:53	40	Kopanice	3	Yes
R 751	17:50	17:53	40	Necpaly	3	Yes
R 751	17:50	17:52	51	Píly	2	Yes
R 751	17:50	17:52	51	Bojnice	2	Yes
R 753	19:50	19:55	40	Kopanice	5	Yes
R 753	19:50	19:55	40	Necpaly	5	Yes
R 753	19:50	20:10	10	Zapotôčky	20	No
R 753	19:50	19:57	51	Píly	7	Yes
R 753	19:50	19:57	51	Bojnice	7	Yes
Os 755	21:52	22:22	83	Kopanice	30	No
Os 755	21:52	22:22	83	Necpaly	30	No
Os 755	21:52	22:15	10	Zapotôčky	23	No
Os 755	21:52	22:07	51	Píly	15	Yes
Os 755	21:52	22:07	51	Bojnice	15	Yes

presents a transfer matrix that complements the existing tables, with the specific example of transfer synchronization evaluation for railway line R7 on weekdays. The structure of Table 6 includes the train identification and arrival time, the departure time of the corresponding urban public transport service, the bus line number, the exact value of the transfer waiting time (calculated as the difference between train arrival and bus departure), and a binary assessment of transfer success based on the defined synchronization interval (accepted waiting time of 5–15 min). This supplementary format provides a clear numerical illustration of how transfers are evaluated in this study and how the original data can be interpreted for transfer quality assessment.

• Line S7 (Prievidza–Topoľčany)

As shown in

Table 7. Connections between line S7 and Prievidza urban public transport services on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5501	5:05	5:12 (40)	5:12 (40)	x	5:06 (51)	5:06 (51)
Os 5505	6:53	7:10 (44)	7:10 (44)	7:05 (10)	7:05 (10)	7:07 (3/90)
Os 5509	8:53	9:14 (40)	9:14 (40)	8:50 (15)	9:04 (3)	9:04 (3)
Os 5513	10:53	11:13 (40)	11:13 (40)	11:08 (15)	11:07 (3)	11:07 (3)
Os 5517	12:53	13:13 (40)	13:13 (40)	13:02 (10)	13:02 (10)	13:09 (3)
Os 5521	14:53	15:14 (40)	15:14 (40)	15:13 (15)	14:59 (51)	14:59 (51)
Os 5525	16:53	17:13 (40)	17:13 (40)	17:02 (10)	17:02 (3)	17:02 (3)
Os 5529	18:53	18:57 (44)	18:57 (44)	x	19:05 (3)	19:05 (3)
Os 5533	20:44	21:13 (40)	21:13 (40)	20:52 (10)	20:52 (51)	20:52 (51)
Os 5537	22:53	x	x	x	x	x
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5502	5:21	5:20 (44)	5:20 (44)	5:19 (10)	5:12 (40)	x
Os 5506	7:14	7:09 (15/44)	7:09 (44)	6:54 (10)	7:02 (50)	7:02 (50)
Os 5510	9:14	9:10 (44)	9:10 (44)	9:12 (10/90)	9:04 (50)	9:04 (50)
Os 5514	11:14	11:08 (15)	11:10 (44)	11:04 (10)	11:04 (10)	11:12 (50)
Os 5518	13:14	13:11 (44)	13:11 (44)	13:04 (10)	13:03 (50)	13:03 (50)
Os 5522	15:14	15:13 (15/44)	15:13 (44)	14:56 (10)	15:05 (50)	15:05 (50)
Os 5526	17:14	17:10 (44)	17:10 (44)	17:08 (90)	17:05 (50)	17:08 (90)
Os 5530	19:14	18:47 (40)	18:47 (40)	19:09 (10)	19:01 (50)	19:01 (50)
Os 5534	21:14	20:47 (40)	20:47 (40)	21:14 (10)	21:13 (40)	x
Os 5536	22:25	x	x	x	x	x

and

Table 8. Connections between line S7 and Prievidza urban public transport services on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5505	6:53	7:13 (40)	7:13 (40)	7:14 (10)	7:12 (51)	7:12 (51)
Os 5509	8:53	x	x	x	9:04 (3)	9:04 (3)
Os 5513	10:53	11:13 (40)	11:13 (40)	x	11:07 (3)	11:07 (3)
Os 5517	12:53	x	x	13:02 (10)	13:02 (10)	13:09 (3)
Os 5521	14:53	15:13 (40)	15:13 (40)	x	15:07 (3)	15:07 (3)
Os 5525	16:53	x	x	17:15 (90)	17:02 (3)	17:02 (3)
Os 5529	18:53	19:13 (40)	19:13 (40)	19:22 (10)	19:05 (3)	19:05 (3)
Os 5533	20:44	x	x	x	20:52 (51)	20:52 (51)
Os 5537	22:53	x	x	x	x	x
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5502	5:21	x	x	x	x	x
Os 5506	7:14	6:49 (40)	6:49 (40)	x	7:02 (50)	7:02 (50)
Os 5510	9:14	x	x	9:12 (90)	9:13 (10)	9:12 (90)
Os 5514	11:14	10:50 (40)	10:50 (40)	11:09 (10)	11:02 (50)	11:02 (50)
Os 5518	13:14	x	x	13:15 (90)	x	13:15 (90)
Os 5522	15:14	14:50 (40)	14:50 (40)	15:06 (10)	15:07 (50)	15:07 (50)
Os 5526	17:14	x	x	17:09 (10)	17:05 (50)	17:05 (50)
Os 5530	19:14	18:47 (40)	18:47 (40)	19:09 (10)	19:09 (10)	18:46 (50)
Os 5534	21:14	x	x	x	x	x

, connections are more accessible on weekdays, but remain limited overall. The residential areas of Kopanice and Necpaly are largely excluded from effective connections to line S7, primarily due to incompatible timing between urban public transport services and the train timetable.

• Line S51 (Prievidza–Vrútky)

Based on the data in

Table 9. Connections between line S51 and Prievidza urban public transport services on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7501	5:12	5:12 (40)	5:12 (40)	5:36 (90)	5:25 (40)	5:34 (15)
Os 7503	7:09	7:16 (15)	7:13 (40)	7:16 (10)	7:16 (10)	7:13 (51)
Os 7509	10:12	10:37 (15)	10:33 (40)	10:22 (10)	10:22 (51)	10:22 (51)
Os 7513	12:12	12:37 (15)	12:33 (40)	12:37 (10)	12:22 (51)	12:22 (51)
Os 7517	14:12	14:25 (83)	14:25 (83)	14:24 (10)	14:25 (51)	14:25 (51)
Os 7521	16:12	16:36 (15)	16:33 (40)	16:27 (10)	16:22 (51)	16:22 (51)
Os 7525	18:12	18:25 (15)	18:33 (40)	18:22 (10)	18:22 (3/51)	18:22 (3/51)
Os 7529	20:09	20:15 (44)	20:15 (44)	20:10 (10)	20:12 (40)	x
Os 7533	22:08	22:22 (83)	22:22 (83)	22:15 (10)	22:15 (10)	22:07 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7502	4:39	x	x	x	x	x
Os 7508	7:44	7:31 (44)	7:32 (40)	7:30 (10)	7:33 (50)	7:33 (50)
Os 7512	9:44	9:30 (40)	9:30 (40)	9:26 (15)	9:34 (50)	9:34 (50)
Os 7516	11:44	11:30 (40)	11:30 (40)	11:42 (15)	11:34 (50)	11:34 (50)
Os 7520	13:44	13:29 (40)	13:29 (40)	13:29 (10)	13:34 (50)	13:34 (50)
Os 7524	15:44	15:31 (40)	15:31 (40)	15:20 (10)	15:34 (50)	15:34 (50)
Os 7528	17:44	17:34 (15)	17:29 (40)	17:24 (10)	17:35 (3)	17:35 (3)
Os 7532	19:37	19:27 (40)	19:27 (40)	19:09 (10)	19:30 (50)	19:30 (50)
Os 7536	22:14	x	x	x	x	x

and

Table 10. Connections between line S51 and Prievidza urban public transport services on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7501	5:12	x	x	x	5:25 (40)	5:36 (51)
Os 7505	8:12	8:33 (40)	8:33 (40)	8:22 (10)	8:22 (10)	8:36 (90)
Os 7509	10:12	x	x	10:17 (10)	10:22 (51)	10:22 (51)
Os 7513	12:12	12:33 (40)	12:33 (40)	x	12:22 (51)	12:22 (51)
Os 7517	14:12	x	x	x	14:17 (51)	14:17 (51)
Os 7521	16:12	16:33 (40)	16:33 (40)	16:17 (10)	16:22 (51)	16:22 (51)
Os 7525	18:12	x	x	18:22 (10)	18:22 (51)	18:22 (51)
Os 7529	20:09	20:33 (40)	20:33 (40)	20:10 (10)	20:12 (40)	x
Os 7533	22:08	x	x	x	22:07 (51)	22:07 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7504	5:44	5:25 (40)	5:25 (40)	x	5:41 (3)	5:41 (3)
Os 7508	7:44	x	x	7:38 (10)	7:38 (10)	x
Os 7512	9:44	9:30 (40)	9:30 (40)	x	9:34 (50)	9:34 (50)
Os 7516	11:44	x	x	11:15 (90)	11:40 (3)	11:40 (3)
Os 7520	13:44	13:29 (40)	13:29 (40)	13:25 (10)	13:32 (50)	13:32 (50)
Os 7524	15:44	x	x	15:41 (10)	15:32 (50)	15:32 (50)
Os 7528	17:44	17:29 (40)	17:29 (40)	x	17:35 (3)	17:35 (3)
Os 7532	19:37	x	x	19:09 (10)	19:13 (40)	x
Os 7536	22:14	x	x	x	x	x

, it can be concluded that transfers in the direction of Handlová–Martin are most suitable for the areas of Píly and Bojnice. The situation is more favourable on weekdays compared to non-working days, when transfer connections are missing for several residential areas.

To improve transfer efficiency, a cyclic coordination model of urban public transport was tested based on the principles of the Integrated Timed-Transfer Timetable. The optimal alignment of time slots was identified as follows:

• Urban public transport arrivals at the 1st and 31st minutes.
• Urban public transport departures at the 5th and 35th minutes.

This model enables the realization of approximately 75% of all possible connections—and more than 90% on weekdays. In major transfer hubs, additional synchronization would be introduced with arrivals at the 16th and 46th minutes and departures at the 20th and 50th minutes.

4.5. Temporal and Spatial Coordination with Regional Bus Transport

The currently operating regional bus transport services that serve the territory of the city of Prievidza are not organized according to a structured line network. Individual services vary in routing; aside from the main transport corridors, they also run through residential areas, thereby partially substituting the functions of urban public transport. This approach emerged in response to passenger demands to minimize transfers between the non-integrated urban public transport and regional bus transport networks.

Due to the lack of fare and operational integration between the two systems, service duplication occurs—especially along the Prievidza–Bojnice corridor. While regional bus transport lines complement the urban public transport offering, they simultaneously create operational inconsistencies. Figure 6 illustrates the routing of regional bus transport services within the cities of Prievidza and Bojnice.

• Possibilities for Replacing Low-Frequency Urban Public Transport Services with Regional Bus Transport

Some regional bus transport lines have the potential to replace minimally operated urban public transport lines. For instance, line 2 (with only sporadic services) could be replaced by a regional bus transport vehicle running counter to the peak traffic direction, thereby making efficient use of available capacity. Similarly, line 7 could potentially be replaced by rerouting line 307434 (Kanianka—Prievidza) via the Bojnice Grammar school stop. Such solutions would make it possible to eliminate low-frequency and low-efficiency urban public transport lines. The frequently operated regional bus transport lines 307426 and 307427, which stop at all urban public transport stops along the Pod skalou–Bus Station segment, have the potential to supplement urban public transport services, particularly line 8. This would allow for a reduction in direct urban public transport lines running all the way to Pod skalou, while optimizing urban public transport vehicle circulations.

• Replacing Regional Bus Transport Services with Coordinated Urban Public Transport

Conversely, in certain cases, it may be appropriate to consider replacing purpose-specific regional bus transport services (commuter lines to industrial zones) with a coordinated urban public transport system that includes transfers. This applies to services covering the Píly, Zapotôčky, and Kopanice residential areas within lines 307,401, 307,410, 307,411, and 307,419, which are directed to industrial sites such as Tatra Pravenec, Fortischem, the power plant, and the mines in Nováky. These services pass through multiple city stops, but offer no significant added value compared to a solution combining urban public transport + regional bus transport with a transfer at the Bus Station stop.

From a temporal coordination perspective, a major issue lies in the fact that regional bus transport lines are not operated at regular intervals (headways). This is particularly problematic with bus line 307434, which runs through areas also served by urban public transport) and operates with a high daily frequency, but without a consistent departure rhythm. This irregularity significantly complicates any systemic coordination with urban public transport, which—according to current professional standards—should be organized within a timed-transfer (headway-based) structure.

The effective integration of urban public transport and regional bus transport networks is contingent upon the unification of core transport parameters—primarily regularity, temporal coordination, and fare integration. The current state, characterized by uncoordinated parallel operations, prevents the realization of synergistic effects between the two systems. Nonetheless, the potential of regional bus transport to replace inefficient urban public transport lines or to supplement high-capacity services is considerable. Realizing this potential requires a clearly defined transport planning strategy.

5. Results

The proposed urban public transport network in Prievidza exhibits a polycentric structure, with the dominant travel relationship occurring between the residential districts of Prievidza and the neighbouring town of Bojnice. A significant transport flow is also observed between the city centre of Prievidza and Bojnice, resulting from the concentration of arrivals of regional bus transport and railway transport services in the Prievidza city centre, followed by passenger transfers to urban public transport lines. Slightly less prominent, but still statistically relevant, are travel flows between individual housing estates, which are above average compared to similarly sized cities. These flows are reflected in the current operation of circulatory lines.

The Integrated Timed-Transfer Timetable system is based on the principle of harmonized public transport timetables operating at regularly repeating intervals with designated transfer nodes in both directions. Ideally, services are mutually synchronized at these nodes, increasing the number of available transfer options. In cases where full synchronization is not feasible, an extended ITTT model may be applied, allowing for partial deviations (differing headways, limited time windows, or reduced service offerings).

An analysis of the territorial and operational conditions shows that the Prievidza–Bojnice area—due to its compact morphology and the presence of a central transfer hub near the railway station—offers favourable conditions for ITTT implementation. Thanks to synchronized arrivals and departures at this hub, the number of direct lines can be significantly reduced, and the entire network can be simplified, while maintaining a high level of service accessibility.

Based on operational and economic considerations, a system headway of 60 min was set as the base interval for the urban public transport network. This interval reflects current demand, supports stable travel times, and is compatible with regional railway services that also operate at 60 min intervals (lines S7 and R7). In the 2024/2025 timetable, departures from Prievidza station are timetabled at minute 14 (S7) and 16 (R7), with arrivals at minute 50 (R7) and 53 (S7).

Considering the defined transfer standards (i.e., between 5 and 15 min), the following time slots were established for urban public transport services at the Bus Station transfer hub: arrivals at the 1st and 31st minutes, and departures at the 5th and 35th minutes. This timing not only ensures compliance with the standard transfer window between urban public transport and railway transport, but also provides a 4 min buffer at the hub as a stabilizing element to absorb potential delays.

Given the base 60 min headway and the existence of two time slots, it is necessary to ensure that each primary radial corridor is served by two lines that are offset by 30 min. This approach enables double the frequency on the most heavily used segments while maintaining operational cost balance. In terms of line design, it is appropriate to aim for one-way travel times of 13 or 26 min, or 26 or 56 min in the case of circular lines, to maintain the rhythm of the timed-transfer hub without unnecessary layovers. Based on an analysis of travel flows throughout the day and the specifics of local demand (a pronounced late-morning off-peak period and less distinct peak periods), it is proposed that, during weekdays from 5:00 to 16:00, the interval be doubled to 30 min. During this time window, two additional symmetric time slots are created at the hub:

• Arrivals at the 16th and 46th minutes;
• Departures at the 20th and 50th minutes.

Figure 7 illustrates the network diagram of the proposed line structure.

5.1. Public Transport Service Design

Our design of the public transport service considered all of the input parameters analyzed in the preceding chapters. The primary objective of the proposal was to achieve maximum efficiency in vehicle circulation while optimizing the allocation of existing transport capacities. Our aim was to improve the quality of service provision across various parts of the city, while simultaneously simplifying the line network and timetables to make them more intuitive and easily memorable for passengers. To ensure the competitiveness of public passenger transport, minimum service standards were defined that reflect the specific characteristics of the studied area. The foundation of the system is the operation of lines at 60 min intervals in the basic service mode. Based on an analysis of travel flows during different times of the day, three operational regimes were defined, as presented in

Table 11. Operational regimes by time of day.

Time Period	Operating Mode	Line Interval	Note
Weekdays, until 4:59	Basic mode (nodes 01/05, 31/35)	60 min; radials: 30 min offset	Standard network coverage
Weekdays, from 17:00	Basic mode (nodes 01/05, 31/35)	60 min; radials: 30 min offset	Standard network coverage
Non-working days, 6:30–20:29	Basic mode (nodes 01/05, 31/35)	60 min; radials: 30 min offset	Standard network coverage
Weekdays, 5:00–16:59	Enhanced mode (nodes 01/05, 16/20, 31/35, 46/50)	30 min; radials: 15 min offset	Double symmetry at transfer node
Non-working days, until 6:29	Limited mode (nodes 16/20 or 31/35)	60 min	Only lines 2, 8 and circular lines 50, 51 operate
Non-working days, from 20:30	Limited mode (nodes 16/20 or 31/35)	60 min	Only lines 2, 8 and circular lines 50, 51 operate

.

The proposed line structure reflects the results of travel flow modelling, as well as the transport-geographical and socio-economic characteristics of the area. In numbering the lines, attention was paid to preserving consistency with existing lines and numbers to ensure that the changes remain intuitive and culturally acceptable for passengers. The numbering system was based on current lines so that the numbers of new lines approximately correspond either to the current lines or use numbers historically associated with the given locality. In practice, any change represents a significant intervention in established passenger habits, and even the numbering of lines plays a key role in whether such changes are perceived positively or negatively by the public. The proposed line scheme is illustrated in Figure 8.

• Example: Proposal of Line 1

Line 1 provides a connection between the city centre and the largest residential area, Zapotôčky, while also offering a tangential link between the neighbourhoods of Zapotôčky and Píly, eliminating the need for transfers in the city centre. In the section from the Bus Station to Zapotôčky, the line is designed to operate in a perfectly offset 30 min pattern with lines 5 and 15. During peak hours, the line is supplemented by line 4, resulting in a 15 min interval. The line has been designed with a travel time of 26 min, allowing for cyclic departures from the Bus Station hub at the 35th minute and returns to the hub at the 1st minute of the following hour. This model enables efficient vehicle circulation without unnecessary layovers.

Table 12. Operational parameters of line 1.

Parameter	Value
Line	Bus Station—Zapotôčky—Píly—Zapotôčky—Bus Station
Main Stops	L. N. Tolstého, Ľ. Ondrejova, Uniklinika, Zimný štatión, Sama Chalupku, Janka Kráľa, Kino Baník, Magura
Length	8.8 km
Interval	30 min (weekdays 5:00–17:00) 60 min (other periods)
Travel Time	26 min
Daily Vehicle Requirement	1 vehicle (weekdays) 0.5 vehicle (non-working days)

presents the operational parameters of Line 1.

The line visualization for line 1 is presented in Figure 9. In terms of vehicle circulation, line 1 is operationally linked with lines 5 and 15, enabling direct service toward the Kopanice district. During enhanced service periods, it is also connected with line 2, which serves the industrial zone. This same approach was applied to the design of other lines (2, 3, 4, 5, 8, 14, 15, 50, 51, 83), which are included in the Supplementary Materials accompanying this article.

5.2. Temporal and Spatial Connectivity of the Proposed Urban Public Transport Network with Railway Transport

Based on the criteria used to analyze the connectivity between railway transport and urban public transport in the existing timetable, the same analysis was conducted for the proposed system. Our objective was to assess the extent to which the proposed urban public transport lines provide functional transfer connections to the individual railway lines (R7, S7, S51).

• Connectivity with Line R7 (Prievidza–Bratislava)

On both weekdays and non-working days, nearly full connectivity is ensured for all arrivals and departures of trains on line R7, except for the early morning train Os 740 at 4:10, for which the urban public transport connection was omitted due to a very low passenger count (on average, one person). Transfers during such extreme time slots were not maintained even on non-working days, due to the limited operational mode of urban public transport services. All other transfers take place at the “Bus Station” hub, where a systematic transfer time of 12–13 min is guaranteed.

Table 13. Connections between line R7 and proposed urban public transport services in Prievidza on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
R 741	7:50	8:05 (50)	8:05 (50)	8:05 (1)	8:05 (51)	8:05 (51)
R 743	9:50	10:05 (50)	10:05 (50)	10:05 (1)	10:05 (51)	10:05 (51)
R 745	11:50	12:05 (50)	12:05 (50)	12:05 (1)	12:05 (51)	12:05 (51)
R 747	13:50	14:05 (50)	14:05 (50)	14:05 (1)	14:05 (51)	14:05 (51)
R 749	15:50	16:05 (50)	16:05 (50)	16:05 (1)	16:05 (51)	16:05 (51)
R 751	17:50	18:05 (5)	18:05 (5)	18:05 (15)	18:05 (51)	18:05 (51)
R 753	19:50	20:05 (5)	20:05 (5)	20:05 (15)	20:05 (51)	20:05 (51)
Os 755	21:52	22:05 (5)	22:05 (5)	22:05 (15)	22:05 (51)	22:05 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 740	4:10	x	x	x	x	x
R 742	6:16	6:01 (51)	6:01 (51)	6:01 (1)	6:01 (50)	6:01 (50)
R 744	8:16	8:01 (51)	8:01 (51)	8:01 (1)	8:01 (50)	8:01 (50)
R 746	10:16	10:01 (51)	10:01 (51)	10:01 (1)	10:01 (50)	10:01 (50)
R 748	12:16	12:01 (51)	12:01 (51)	12:01 (1)	12:01 (50)	12:01 (50)
R 750	14:16	14:01 (51)	14:01 (51)	14:01 (1)	14:01 (50)	14:01 (50)
R 752	16:16	16:01 (51)	16:01 (51)	16:01 (1)	16:01 (50)	16:01 (50)
R 754	18:16	18:01 (51)	18:01 (51)	18:01 (1)	18:01 (3)	18:01 (3)

shows the connections between line R7 and the proposed urban public transport services in Prievidza on weekdays, while

Table 14. Connections between line R7 and proposed urban public transport services in Prievidza on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
R 741	7:50	8:05 (5)	8:05 (5)	8:05 (15)	8:05 (51)	8:05 (51)
R 743	9:50	10:05 (5)	10:05 (5)	10:05 (15)	10:05 (51)	10:05 (51)
R 745	11:50	12:05 (5)	12:05 (5)	12:05 (15)	12:05 (51)	12:05 (51)
R 747	13:50	14:05 (5)	14:05 (5)	14:05 (15)	14:05 (51)	14:05 (51)
R 749	15:50	16:05 (5)	16:05 (5)	16:05 (15)	16:05 (51)	16:05 (51)
R 751	17:50	18:05 (5)	18:05 (5)	18:05 (15)	18:05 (51)	18:05 (51)
R 753	19:50	20:05 (5)	20:05 (5)	20:05 (15)	20:05 (51)	20:05 (51)
Os 755	21:52	x	x	x	x	x
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 740	4:10	x	x	x	x	x
R 742	6:16	x	x	x	x	x
R 744	8:16	8:01 (51)	8:01 (51)	8:01 (1)	8:01 (3)	8:01 (3)
R 746	10:16	10:01 (51)	10:01 (51)	10:01 (1)	10:01 (3)	10:01 (3)
R 748	12:16	12:01 (51)	12:01 (51)	12:01 (1)	12:01 (3)	12:01 (3)
R 750	14:16	14:01 (51)	14:01 (51)	14:01 (1)	14:01 (3)	14:01 (3)
R 752	16:16	16:01 (51)	16:01 (51)	16:01 (1)	16:01 (3)	16:01 (3)
R 754	18:16	18:01 (51)	18:01 (51)	18:01 (1)	18:01 (3)	18:01 (3)

presents the connections on non-working days and non-working days.

• Connectivity with Line S7 (Prievidza–Topoľčany)

For regional trains on line S7, connections are provided during all key time slots on weekdays, except for several trains that deviate significantly from the standard headway timetable (trains 5502, 5533, 5536). Their timing outside the coordinated transfer hub makes it impossible to ensure systematic transfers without disrupting the overall coordination of the urban public transport network. Therefore, within the proposed timed-transfer system of the urban public transport system, it is not feasible to adapt individual services to these outliers. A possible solution would involve a timetable for adjustment within the railway timetable.

Table 15. Connections between line S7 and proposed urban public transport services in Prievidza on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5501	5:05	5:20 (5)	5:20 (5)	5:20 (15)	5:20 (3)	5:20 (3)
Os 5505	6:53	7:05 (50)	7:05 (50)	7:05 (1)	7:05 (51)	7:05 (51)
Os 5509	8:53	9:05 (50)	9:05 (50)	9:05 (1)	9:05 (51)	9:05 (51)
Os 5513	10:53	11:05 (50)	11:05 (50)	11:05 (1)	11:05 (51)	11:05 (51)
Os 5517	12:53	13:05 (50)	13:05 (50)	13:05 (1)	13:05 (51)	13:05 (51)
Os 5521	14:53	15:05 (50)	15:05 (50)	15:05 (1)	15:05 (51)	15:05 (51)
Os 5525	16:53	17:05 (5)	17:05 (5)	17:05 (15)	17:05 (51)	17:05 (51)
Os 5529	18:53	19:05 (5)	19:05 (5)	19:05 (15)	19:05 (51)	19:05 (51)
Os 5533	20:44	21:05 (5)	21:05 (5)	21:05 (15)	21:05 (51)	21:05 (51)
Os 5537	22:53	x	x	x	x	x
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5502	5:21	5:01 (51)	5:01 (51)	5:16 (5)	5:01 (50)	5:01 (50)
Os 5506	7:14	7:01 (51)	7:01 (51)	7:01 (1)	7:01 (50)	7:01 (50)
Os 5510	9:14	9:01 (51)	9:01 (51)	9:01 (1)	9:01 (50)	9:01 (50)
Os 5514	11:14	11:01 (51)	11:01 (51)	11:01 (1)	11:01 (50)	11:01 (50)
Os 5518	13:14	13:01 (51)	13:01 (51)	13:01 (1)	13:01 (50)	13:01 (50)
Os 5522	15:14	15:01 (51)	15:01 (51)	15:01 (1)	15:01 (50)	15:01 (50)
Os 5526	17:14	17:01 (51)	17:01 (51)	17:01 (1)	17:01 (50)	17:01 (50)
Os 5530	19:14	19:01 (51)	19:01 (51)	19:01 (1)	19:01 (50)	19:01 (50)
Os 5534	21:14	21:01 (51)	21:01 (51)	21:01 (1)	21:01 (50)	21:01 (50)
Os 5536	22:25	22:01 (51)	22:01 (51)	22:01 (1)	22:01 (1)	x

and

Table 16. Connections between line S7 and proposed urban public transport services in Prievidza on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5505	6:53	7:05 (5)	7:05 (5)	7:05 (15)	7:05 (51)	7:05 (51)
Os 5509	8:53	9:05 (5)	9:05 (5)	9:05 (15)	9:05 (51)	9:05 (51)
Os 5513	10:53	11:05 (5)	11:05 (5)	11:05 (15)	11:05 (51)	11:05 (51)
Os 5517	12:53	13:05 (5)	13:05 (5)	13:05 (15)	13:05 (51)	13:05 (51)
Os 5521	14:53	15:05 (5)	15:05 (5)	15:05 (15)	15:05 (51)	15:05 (51)
Os 5525	16:53	17:05 (5)	17:05 (5)	17:05 (15)	17:05 (51)	17:05 (51)
Os 5529	18:53	19:05 (5)	19:05 (5)	19:05 (15)	19:05 (51)	19:05 (51)
Os 5533	20:44	x	x	x	x	x
Os 5537	22:53	x	x	x	x	x
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 5502	5:21	5:16 (51)	5:16 (51)	x	5:16 (50)	5:16 (50)
Os 5506	7:14	7:01 (51)	7:01 (51)	7:01 (1)	7:01 (3)	7:01 (3)
Os 5510	9:14	9:01 (51)	9:01 (51)	9:01 (1)	9:01 (3)	9:01 (3)
Os 5514	11:14	11:01 (51)	11:01 (51)	11:01 (1)	11:01 (3)	11:01 (3)
Os 5518	13:14	13:01 (51)	13:01 (51)	13:01 (1)	13:01 (3)	13:01 (3)
Os 5522	15:14	15:01 (51)	15:01 (51)	15:01 (1)	15:01 (3)	15:01 (3)
Os 5526	17:14	17:01 (51)	17:01 (51)	17:01 (1)	17:01 (3)	17:01 (3)
Os 5530	19:14	19:01 (51)	19:01 (51)	19:01 (1)	19:01 (3)	19:01 (3)
Os 5534	21:14	x	x	x	21:01 (3)	21:01 (3)

present the connections between line S7 and the proposed urban public transport services in Prievidza on weekdays and non-working days.

• Connectivity with Line S51 (Prievidza–Vrútky)

Rail line S51 represents a specific case. In the direction toward Vrútky, transfers are ensured throughout the entire week, while in the opposite direction from Vrútky, functional connections to urban public transport are only provided on weekdays. On non-working days, due to a temporal mismatch, the transfer time extends up to 23 min, which reduces the attractiveness of combined travel. This imbalance resulted from past timetable shifts that moved S51 trains outside the timed-transfer hub, aiming to improve rail service punctuality and reduce delays. Given the 30 min base interval of urban public transport, it is not technically feasible to provide two-way connections for all services. For this reason, an asymmetric transfer model was adopted, prioritizing connections in the direction toward Vrútky. This approach is justified by the lower relevance of line S51 in the regional transport system, the availability of alternative connections (regional bus services), and the limited competitiveness of rail transport on the Prievidza—Žilina line.

Table 17. Connections between line S51 and proposed urban public transport services in Prievidza on weekdays.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7501	5:12	5:20 (5)	5:20 (5)	5:20 (15)	5:20 (3)	5:20 (3)
Os 7503	7:09	7:20 (5)	7:20 (5)	7:20 (15)	7:20 (3)	7:20 (3)
Os 7509	10:12	10:20 (5)	10:20 (5)	10:20 (15)	10:20 (3)	10:20 (3)
Os 7513	12:12	12:20 (5)	12:20 (5)	12:20 (15)	12:20 (3)	12:20 (3)
Os 7517	14:12	14:20 (5)	14:20 (5)	14:20 (15)	14:20 (3)	14:20 (3)
Os 7521	16:12	16:20 (5)	16:20 (5)	16:20 (15)	16:20 (3)	16:20 (3)
Os 7525	18:12	18:35 (50)	18:35 (50)	18:35 (1)	18:35 (3)	18:35 (3)
Os 7529	20:09	20:35 (50)	20:35 (50)	18:35 (1)	20:35 (3)	20:35 (3)
Os 7533	22:08	23:35 (50)	23:35 (50)	18:35 (1)	22:35 (3)	22:35 (3)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7502	4:39	x	x	x	x	x
Os 7508	7:44	7:31 (51)	7:31 (51)	7:31 (1)	7:31 (50)	7:31 (50)
Os 7512	9:44	9:31 (51)	9:31 (51)	9:31 (1)	9:31 (50)	9:31 (50)
Os 7516	11:44	11:31 (51)	11:31 (51)	11:31 (1)	11:31 (50)	11:31 (50)
Os 7520	13:44	13:31 (51)	13:31 (51)	13:31 (1)	13:31 (50)	13:31 (50)
Os 7524	15:44	15:31 (51)	15:31 (51)	15:31 (1)	15:31 (50)	15:31 (50)
Os 7528	17:44	17:31 (15)	17:31 (15)	17:31 (5)	17:31 (50)	17:31 (50)
Os 7532	19:37	19:31 (15)	19:31 (15)	19:31 (5)	19:31 (50)	19:31 (50)
Os 7536	22:14	22:01 (51)	22:01 (51)	22:01 (1)	x	x

and

Table 18. Connections between line S51 and proposed urban public transport services in Prievidza on non-working days.

Train	Arrival	Connections to Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7501	5:12	5:20 (50)	5:20 (50)	x	5:20 (51)	5:20 (51)
Os 7505	8:12	8:35 (50)	8:35 (50)	8:35 (1)	8:35 (3)	8:35 (3)
Os 7509	10:12	10:35 (50)	10:35 (50)	10:35 (1)	10:35 (3)	10:35 (3)
Os 7513	12:12	12:35 (50)	12:35 (50)	12:35 (1)	12:35 (3)	12:35 (3)
Os 7517	14:12	14:35 (50)	14:35 (50)	14:35 (1)	14:35 (3)	14:35 (3)
Os 7521	16:12	16:35 (50)	16:35 (50)	16:35 (1)	16:35 (3)	16:35 (3)
Os 7525	18:12	18:35 (50)	18:35 (50)	18:35 (1)	18:35 (3)	18:35 (3)
Os 7529	20:09	20:35 (50)	20:35 (50)	x	20:35 (3)	20:35 (3)
Os 7533	22:08	22:35 (50)	22:35 (50)	x	22:35 (51)	22:35 (51)
Train	Departure	Connections from Direction
		Kopanice	Necpaly	Zapotôčky	Píly	Bojnice
Os 7504	5:44	5:16 (51)	5:16 (51)	x	5:16 (50)	5:16 (50)
Os 7508	7:44	7:31 (15)	7:31 (15)	7:31 (5)	7:31 (50)	7:31 (50)
Os 7512	9:44	9:31 (15)	9:31 (15)	9:31 (5)	9:31 (50)	9:31 (50)
Os 7516	11:44	11:31 (15)	11:31 (15)	11:31 (5)	11:31 (50)	11:31 (50)
Os 7520	13:44	13:31 (15)	13:31 (15)	13:31 (5)	13:31 (50)	13:31 (50)
Os 7524	15:44	15:31 (15)	15:31 (15)	15:31 (5)	15:31 (50)	15:31 (50)
Os 7528	17:44	17:31 (15)	17:31 (15)	17:31 (5)	17:31 (50)	17:31 (50)
Os 7532	19:37	19:31 (15)	19:31 (15)	19:31 (5)	19:31 (50)	19:31 (50)
Os 7536	22:14	x	x	x	x	x

present the connections between line S51 and proposed urban public transport services in Prievidza on weekdays and non-working days.

6. Discussion

The proposed urban public transport line network system for the city of Prievidza represents a fundamental systemic transformation, with the primary objectives of improving the efficiency of transport service provision, reducing operational costs, and enhancing connectivity with railway transport. This discussion summarizes the key outcomes of the proposal in terms of operational efficiency, economic indicators, technological considerations, and organizational rationalization.

A comparison of the current state and the proposed system was conducted for each railway line, focusing on the share of suitable, unsuitable, and non-existent transfers between urban public transport and train services.

A comparison of connectivity between urban public transport and railway line R7 is presented in Table 13 and Table 14. On weekdays, the share of suitable transfers increased from 63% to 94%, while unsuitable transfers were eliminated (reduced from 34% to 0%). A slight increase in non-existent transfers (from 4% to 6%) is related to the limitation of early-morning urban public transport services. On non-working days, improvements were observed across all categories: suitable transfers increased from 35% to 81%, unsuitable decreased from 23% to 0%, and non-existent decreased from 43% to 19%.

For line S7, connectivity also improved significantly. On weekdays, the share of suitable transfers rose from 40% to 80%, unsuitable transfers dropped from 43% to 14%, and non-existent ones dropped from 17% to 6%. On non-working days, suitable transfers increased sharply from 26% to 80%, while unsuitable and non-existent transfers fell from 33% to 4% and from 41% to 16%, respectively.

The development of connectivity for line S51 showed a weekday increase in suitable transfers from 63% to 76%, a reduction in unsuitable ones from 22% to 17%, and a decrease in non-existent transfers from 14% to 8%. On non-working days, although the share of suitable transfers rose from 31% to 43%, the share of unsuitable transfers also increased (from 30% to 47%), which is linked to the temporal alignment of urban public transport services in the base timetable. Nevertheless, there was a significant reduction in train services without any urban public transport connection—from 39% to 10%.

The implementation of the proposed timetables would bring about a substantial improvement in urban public transport–rail connectivity in Prievidza. The greatest benefits would be seen in the districts of Kopanice, Necpaly, and Zapotôčky, where the share of suitable transfers to line R7 on weekdays would increase from 50–56% to 94%, and on non-working days from 25% to 80%. The proposed system also eliminates the need to memorize exceptions and offers consistent and reliable public transport service. One of the key benefits of the proposed system is the significant increase in vehicle and driver productivity. The new routing and timed-transfer organization allowed for a reduction in non-revenue (deadhead) trips, more efficient shift planning, and the introduction of systematic breaks. Of the total number of kilometres driven, only 5.69% were non-revenue kilometres, which is significantly below the average for comparable transport systems.

In terms of vehicle circulation, the number of vehicles required on weekdays was reduced from the current 33 to 18. After including a 20% operational reserve, a total of 22 vehicles would be sufficient to provide full weekly service coverage. By optimizing driver shifts, the total volume of working hours was reduced by 28.43%, while the total output (vehicle kilometres) decreased by only 20.01%, indicating higher labour productivity.

To demonstrate the impact of the proposed optimization procedure based on the principles of the Integrated Timed-Transfer Timetable, a comparative analysis of the selected key performance indicators was conducted. The results in

Table 19. Comparison of key performance indicators before and after network optimization.

Indicator	Before Optimization	After Optimization	Change
Number of lines	12	8	−33%
Total daily performance (vehicle km/day)	4080	2720	−33%
Share of guaranteed transfers (%)	45	82	37%
Average transfer waiting time (min)	12.5	7.2	−5.3 min
Average number of transfers per trip	1.5	1.2	−0.3
Share of population served (%)	87	95	8%
Number of required vehicles	22	17	−23%
Estimated operating costs (%)	100	80	−20%

demonstrate that the implementation of the Integrated Timed-Transfer Timetable principles leads to improvements in transfer reliability, reduced operational costs, and higher coverage of the served area.

Assuming a unit cost of EUR 2.875 per vehicle kilometre, the total annual compensation paid by the municipalities for urban public transport services would decrease from EUR 3.70 million to approximately EUR 2.95 million, representing a saving of more than EUR 740,000. The city of Prievidza would save around EUR 745,000, while the contribution of the city of Bojnice would slightly increase due to the recalculated share of service performance on its territory (from 5.43% to 6.4%). However, this difference is marginal compared to the overall benefits of the proposal.

Another major area of savings involves vehicle depreciation. If the vehicle fleet were reduced by 11 buses (from 33 to 22), annual depreciation savings could reach up to EUR 231,000, based on a conservative estimate with a ten-year vehicle lifespan. Additional savings can also be expected in terms of wage and administrative costs, although quantifying these would require a dedicated operational audit. In terms of outputs, the total annual volume of tariff kilometres would amount to 1,027,827 vehicle kilometres, which is a 20% reduction compared to the current figure of 1,286,031 vehicle kilometres. Despite this, the full-service offering is maintained along the main transport corridors, while service regularity, predictability, and connectivity with railway transport are significantly improved.

Table 20. Overview of transport performance (in vehicle kilometres) for proposed lines.

Line	Weekday		Non-Working Days		Total Annual Transport Performance
	Daily	Annual	Daily	Annual
1	264.0	66,000	123.2	14,168	80,168
2	286.3	71,575	106.9	12,294	83,869
3	373.0	93,250	142.5	16,388	109,638
4	124.8	31,200	-	-	31,200
5	290.0	72,500	140.0	16,100	88,600
8	528.4	132,100	355.2	40,848	172,948
14	151.2	37,800	-	-	37,800
15	281.3	70,325	135.8	15,617	85,942
50	495.8	123,950	295.4	33,971	157,921
51	489.0	122,250	302.1	34,742	156,992
83	91.0	22,750	-	-	22,750
Total	3374.8	843,700	1601.1	184,127	1,027,827

summarizes the performance of the urban public transport network before and after the implementation of the optimization model. The results confirm significant improvements in transfer synchronization, service area coverage, operational efficiency, and economic costs.

The proposed system also considers the current technical base of the public transport operator SAD Prievidza and the planned acquisition of 16 new electric buses. The Solaris Urbino 10.5 midibuses, of which nine units are currently available, are identified as being significantly oversized in the context of the proposed network. Their potential withdrawal or reassignment to other operations does not represent an issue, as they were purchased from internal resources and are not bound by subsidy mechanisms. The proposed solution enhances the accessibility of public transport in city areas that are currently served irregularly or with suboptimal transfer connections. Through the implementation of a fixed-interval integrated timetable and systematic transfer coordination, the integration with regional railway services is significantly improved. For example, on line R7, the share of optimal connections during non-working days increases from 35% to 81%, thereby offering residents a more attractive, reliable, and time-consistent transport service.

The results of the proposed model are directly applicable to public transport planning. To further support the sustainability and replicability of the system in other regions, future research should focus on several key areas. Testing the applicability of the proposed model in towns of similar sizes and urban structures would help verify its generalizability. Moreover, it is important to quantify the environmental benefits of reducing total vehicle kilometres and deploying electric buses. Advanced data sources, including GPS tracking, mobile network data, travel cards, and onboard sensors, should be utilized to model actual passenger behaviour. This would enable the design of adaptive lines and service frequencies that are responsive to real-time demand. Additionally, passenger surveys conducted before and after the implementation of the new network design could help identify the satisfaction of drivers and their possible resistance to change. Finally, attention should be given to identifying alternative solutions for maintaining minimum service levels during unexpected disruptions such as pandemics, operational closures, or workforce shortages, while ensuring integration with regional and intermodal transport systems.

7. Conclusions

The objective of the proposed new line network and fixed-interval timetable was to create an efficient, functional, and financially sustainable model of an urban public transport system for a medium-sized city, reflecting current demands for modern transport systems while drawing on proven domestic and international practices, particularly from the European context. Within the proposal, an integrated interval timetable was developed, respecting the existing time slots of regional railway services. This ensured optimal transfer connections while minimizing transfer times for intra-city commuting. The chosen system enables a denser interval structure compared to the existing state, and, at the same time, guarantees higher operational stability and comfort for passengers. The analysis demonstrated that the application of integrated interval timetable principles can result in more efficient transport performance, a reduced need for fleet size, and optimized operational costs, all without negatively affecting the scope or quality of the transport on offer. Greater efficiency was also achieved through optimized vehicle circulation and driver scheduling, which contributes to the better utilization of the fleet and human resources.

The practical contribution of this work lies in its successful implementation of theoretical knowledge from the field of public transport planning and organization to the specific conditions of the city of Prievidza. The analysis results and the proposed system can be directly utilized by municipalities and operators as a foundation for decision-making processes, adjustments of contractual frameworks, or the development of future transport policies. The work also highlights systemic and legislative shortcomings affecting the organization of public transport in smaller cities whose resolution requires a comprehensive approach beyond the scope of this study. Nevertheless, the submitted analysis can serve as a reference document for further research, as well as for the preparation of legislative or strategic frameworks in the field of sustainable mobility.