Integrated Clock-Face Timetable as a Tool for Optimizing the Municipal Public Transport System in the City of Ludbreg and Surrounding Municipalities

Abstract

Through the Study on the Development of a Sustainable Public Transport System and a Non-Motorized Mobility System, in October 2022, the City of Ludbreg and the local municipalities of Martijanec, Sveti Đurđ, Veliki Bukovec, and Mali Bukovec jointly agreed to develop a sustainable transport system focused on passenger mobility. This agreement included co-financing the Study, which supports local development and promotes the efficient use of EU funds allocated for the 2021–2027 period. The Study emphasizes the integration of public transport, walking, and cycling, alongside the sustainable use of private vehicles, in alignment with European and national strategic frameworks aimed at reducing CO₂ emissions and improving quality of life. However, the City of Ludbreg aims to further enhance the municipal public transport system, not only within the city but also across the entire Northern Croatia region. As a first step, in addition to optimizing the existing public transport service and defining an optimal bus route network, the goal is to establish a modern public transport system that is more attractive to users, offers greater comfort, ensures higher accessibility, and minimizes negative environmental impacts. By improving service quality, the system is expected to attract more users and create new mobility opportunities, contributing to demographic revitalization, employment growth, environmental protection, energy efficiency, lower transport costs, an improved standard of living, and broader economic development in Ludbreg and the surrounding region.

1. Introduction

To improve urban quality of life, cities and regions around the world are increasingly investing in sustainable urban transport systems, especially public transport systems. A key component of these systems is the development of long-term, viable public transport networks. Numerous studies confirm that transit demand positively correlates with population density, employment levels, and land-use intensity [1].

In addition, previous research highlights that land-use characteristics such as population density, mixed land-use patterns, and street network design have a significant influence on public transport ridership and overall mobility behavior [2,3,4].

In densely populated urban areas, it is generally easier to attract people to use public transport due to shorter travel distances, lower car ownership, higher service efficiency, and a greater concentration of population and commercial activity [5,6].

Because of shorter travel distances, it is easier to make trips without a car in dense areas, so residents in such environments are more likely to choose alternative modes, including public transport. While other land-use variables are also important, and population density may not be the most important, it is the simplest variable to measure at a city-wide level for a nationwide sample of cities [7]. By contrast, designing feasible and effective public transport systems in smaller towns and rural communities remains a significant challenge. Low population density, dispersed settlement structures, limited financial resources, and declining demographic trends all contribute to weak transport demand and car dependency.

This article presents findings from a study that aimed to explore whether an integrated public transport system—with regular connections and a clock-face or pulse timetable (e.g., services every 60 min)—can increase ridership and encourage a modal shift toward sustainable mobility in small urban and semi-rural communities. This research is grounded in empirical data collected during the preparation of two key transport planning documents completed in 2022 and 2024: the Traffic Study for the Introduction of Zero-Emission Vehicles into the Public City Transport System of the City of Ludbreg [8] and the Study on the Development of a Sustainable Public Transport System and a Non-Motorized Mobility System for the City of Ludbreg, and the Municipalities of Martijanec, Sveti Đurđ, Veliki Bukovec, and Mali Bukovec [9]. These documents clearly indicate that these communities are seeking to improve their current, underperforming public transport systems and to reduce car dependency. According to the 2021 Census, this microregion had a combined population of 17,650 and a total area of 228.34 km². Since 1953, the population has been declining. While Ludbreg’s population increased until 2001, peaking at 9460, it has since fallen to 8519 in 2021. The surrounding municipalities have experienced even more severe losses—between 40% and 45% over the same period [10]. Despite this, Ludbreg remains the economic, social, and educational centre of the microregion, with surrounding settlements dependent on it for employment, services, and education. The city’s development index stands at 105, above the national average [11]. Local authorities have prioritised sustainable mobility policies that include integrated public transport and increased shares of walking and cycling. These efforts align with European strategic goals such as the European Green Deal and the EU’s Sustainable and Smart Mobility Strategy (2020), which advocate for cleaner, more inclusive, and better-connected transport systems across Europe, including rural and remote areas. In the context of sustainable mobility, public transport is seen not merely as a service, but as a social and environmental enabler. According to current frameworks, sustainable mobility encompasses transport systems that are accessible, low-emission, economically viable, and socially inclusive.

While there is growing attention to sustainable mobility in larger cities, there remains a lack of research focused on the applicability of integrated timetable models in smaller, low-density urban and rural settings. This article aims to address that gap by presenting a case study from Northern Croatia and evaluating how integrated public transport services can enhance mobility, support economic and demographic revitalisation, and contribute to long-term regional sustainability.

2. Methodology

The research applied a combination of qualitative and quantitative methods to assess the current state of public transport demand and infrastructure in Ludbreg and the surrounding municipalities. The methods used for this article were: traffic counts in road traffic method, passenger counts in public transport systems method, observation method, survey method (questionnaire for general public), statistical method, and analysis method [12].

As part of the analysis, traffic counts were conducted at 15 intersections in the city of Ludbreg. The aim of these counts was to assess the load on the road network and identify areas with high traffic intensity that may affect the efficiency and availability of public transport. Passenger counts were conducted at key transport nodes: the Ludbreg railway station and the central bus stop. Manual counts were performed by trained staff during peak (6:00–9:00, 14:00–17:00) and off-peak periods. Observations were recorded at 15 min intervals and included boarding and alighting data per vehicle. The goal was to capture daily variability and typical usage levels of existing transport services. A structured survey was designed to assess the travel behaviour, preferences, and willingness of citizens to use improved public transport services. The survey included both closed and open-ended questions, and covered topics such as trip frequency, preferred transport modes, reasons for mode choice, and desired service features. The sampling strategy followed a stratified random model, ensuring proportional representation of residents from the city of Ludbreg, suburban settlements, and surrounding rural municipalities. Questionnaires were distributed both online (via municipal websites and social media channels) and in person at municipal buildings, markets, and health centres. A total of 688 responses were collected, corresponding to an estimated response rate of 12.4%, based on the target population. Responses were analysed using descriptive statistics and cross-tabulation by demographic group and location [9].

The proposed transport network variants were developed based on the identified mobility needs and spatial distribution of demand. The concept of a clock-face timetable was adopted to ensure regular and predictable connections between lines, with coordinated transfers to rail and regional bus services. The timetable structure is based on fixed departure intervals (every 60 min), synchronised at key transfer nodes. The design is based on London’s Underground Railway System map designed by Henry Charles Beck in 1933. By the early 1930s, the London Underground network had expanded so much that it was increasingly difficult to squeeze all the new lines and stations into a geographical map. Passengers complained that the existing map was crowded, confusing, and hard to read. The network was too big to be represented geographically [13]. Unintimidated by cartographic convention, Henry Charles Beck, an electrical draughtsman from Finchley who was at that time temporarily employed by the London Underground Signals Office to create a simplified version that set the principles of today’s diagram [14]. He used only vertical, horizontal, or 45-degree angled coloured lines; located the stations according to available space; and evened out the distances between stations [15]. The only slightly realistic element included in the map was the Thames River. According to [14], this was a clever use of landmark that helps the user interpret the diagram. The resulting “map”, although geographically inaccurate, provided a coherent overview of a complex system [14]. The map was an instant success for Londoners and rapidly structured their image of the city. According to Tufte [16], “the map organized London, rather than London organizing the map”. Beck’s map was produced on a trial basis in 1933 as a leaflet, and Beck continued to refine it until 1959. His design has inspired the maps of many cities around the world, and a variation of his original design is still used by London Underground today [13,14,15,17].

Beck’s design was combined with the use of timetables based on time-transfer systems, or pulse timetable systems, or pulse systems, or integrated clock-face timetables [18,19,20,21,22,23]. This was done to allow interchanges between all the lines in the system and to maximize the accessibility of the entire area covered by the system.

While not the primary focus of this study, basic financial estimates of operational costs were calculated using unit price assumptions derived from transport operator data. These included vehicle-kilometre costs, estimated staff expenses, fuel/energy use, and maintenance.

Fare revenue assumptions were based on projected ridership and average ticket prices. A more detailed financial breakdown is provided in Section 5 (Financial Analysis).

3. Literature Review

Improving the public transport system within a community can yield numerous benefits for sustainability, economic growth, and quality of life. Designing and implementing effective public transport systems in small towns and rural areas presents unique challenges that differ from those in large, densely populated urban centres. This literature review explores four key areas relevant to this study: the challenges of public transport in low-density areas, the broader benefits of public transport in small communities, strategies for integrated and user-friendly transport systems, and the policy frameworks that support sustainable rural mobility. Together, these themes provide a foundation for the development of an integrated public transport system for the local community that includes Ludbreg and surrounding communities.

Ridership tends to increase when either the quantity or quality of service improves. The model includes one independent variable for service quantity, measured as vehicle revenue hours, and two variables for service quality: frequency and span of service [7]. Numerous studies confirm that factors such as residential density, walkability, land-use mix, and access to amenities significantly influence public transport usage [2,3,4,5]. However, broader empirical studies on this topic remain limited, especially for rural and low-density contexts.

Clock-face timetables—also referred to as pulse or cyclic timetables—are efficient timetable systems for low-density suburban areas where frequencies of departures are low, meaning that the vehicles depart every 20, 30, or 60 min, or even more. But such systems can offer connections between the lines and can offer accessibility for the entire system, even if the density of living and economic activities is low [18,19,20,21,22,23].

Public transport can be more attractive when it offers door-to-door mobility, and development of transportation services is an important contributor to social quality [24]. Sustainability of transportation, environmental conditions of an area, public health, and economic conditions of residents can be improved by shifting from private transport to public transportation, walking, and cycling [25]. This shift will happen in the condition that the public transportation is widely available and accessible to the public [26].

It is well known that transport generates a certain amount of external costs, which are mostly paid from local, regional, national, and federal budgets [27]. According to the Handbook on External Costs by the European Commission, the total external costs of transport in EU countries amounted to EUR 841.1 billion in 2016, representing 5.7% of the total gross national product of the entire EU [28]. Consequently, transport significantly and devastatingly impacts human health, climate change, and environmental quality. However, public passenger transport generates significantly lower harmful effects than private cars while delivering the same transport efficiency. In terms of space efficiency—particularly in urban areas—sustainable modes of transport, especially walking, cycling, and public transport, offer significant advantages over individual car use [29].

External transport costs include expenses associated with traffic accidents, air pollution, climate change, harmful effects of noise, traffic congestion, the external costs generated by the production and distribution of propulsion energy, destruction of nature and landscapes, water and soil pollution, biodiversity losses, and other similar costs. For every passenger-kilometre travelled by a private car, the average amount of external transport costs in the EU is 12.6 Eurocents. In contrast, urban or suburban bus incurs an average external cost of just 3.8 Eurocents per passenger-kilometre [30].

A well-developed public transport system generates numerous direct and indirect benefits for both individuals and society as a whole [31].

Transport marginalization, which leads to social exclusion, has consequences that also affect an individual’s success in education and professional careers [32]. In regions where public transport is either poorly developed or entirely lacking, certain population groups may become marginalised due to limited access to essential services and opportunities.

A statistically significant correlation has been observed between transport marginalization and students’ academic performance, with results also indicating its impact on how they utilize their free time. This shows that they are deprived of educational opportunities, especially extracurricular activities, leading to partial or complete social exclusion from specific experiences and life opportunities [32]. The entire public transport system in Northern Croatia should be restructured, with all bus and rail passenger lines redesigned according to principles of demand and supply. The aim is to improve intercity, regional, and local connectivity, making public transport a more competitive and attractive alternative to private car use [33]. The city of Ludbreg also has goals in its development plan to develop a sustainable transport system [11]. Approximately one-third of the European population resides in villages, small towns, and peri-urban areas on the outskirts of cities, often relying on private cars to reach urban nodes, such as to get to work or school, socialize, travel, or shop. However, this results in a high number of cars entering and leaving urban nodes daily, which has negative repercussions on pollution, congestion, and road safety [34]. The pandemic and the related trend of teleworking have reduced the importance of city centres (empty offices) and increased the importance of peri-urban and rural areas. However, public transport is still very focused on bringing passengers to the city centre in the morning and back to the suburbs in the evening. Many public transport authorities and operators have recently realised that this is no longer the trend and have started to introduce peripheral services [35].

In this context, the EU has emphasized the importance of efficient and inclusive connectivity between rural, peri-urban, and urban areas through sustainable mobility options [36]. It strongly recommends integrating links between rural, suburban, and urban areas in the planning of the TEN-T network, as well as connections between these areas and cities. Additionally, it calls for efficient public transport interchanges with the TEN-T urban nodes and the development of multimodal passenger hubs, including park-and-ride facilities [35].

4. The Analysis of Current Public Transport Supply, Tariffs, Modal Share, and Preferences Towards Potential Usage of Modern Public Transport Systems

This chapter examines the current public transport supply and public transport numbers in relation to the current demand. A short analysis of current tariffs was also done. A citizens’ survey was conducted among many participants. The data were gathered via questionnaire, and the citizens were given answers online and in person.

The most important part of the survey was determining the transport modal share in the region and the preferences of the public towards using a modern, convenient, frequent, and accessible public transport system.

4.1. Analysis of Public Transport Supply

An analysis of the public transport supply by rail determined 12 departures to Varaždin and 10 departures to Koprivnica every working day [9].

The Master Plan for Integrated Passenger Transport [33] anticipates 26 departures during the weekday, with the frequency of departures of 30 min during peak hours, and 60 min off-peak hours and weekends. A summary of this analysis has been presented in

Table 1. Number of departures of local trains from Ludbreg station to Varaždin and to Koprivnica per every hour during working day in 2022.

	Number of Departures per Hour–Situation from 2022
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Ludbreg-Varaždin	1	0	2	0	1	1	0	0	1	1	1	0	0	1	1	1	1	0	0	0
Ludbreg-Koprivnica	1	0	0	1	1	0	1	0	0	1	0	1	1	0	1	1	0	0	1	0
	Number of departures per hour–Master plan standard to be achieved by 2027
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Ludbreg-Varaždin	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Ludbreg-Koprivnica	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1

Legend: red cell—no departures during that hour, light green cell—one departure per hour, dark green—two or more departures per hour. Source: [9,33].

.

The offer in Table 1 is unattractive because several parts of the day are not covered by the service. For example, in the direction of Varaždin, there are two parts of the day where there is no departure for more than two hours. Also, for the same direction, part of the day between 9 PM and midnight is completely without service. The service to Koprivnica also has three parts of the day where service, departures, are missing for more than 2 h. The service during weekends is even more reduced than the one analysed here. Table 1 also shows the standard in the number of departures as planned by the Master Plan for Integrated Passenger Transport. The local rail passenger service has the potential to be integrated with the bus service, offering more accessibility. The integration of the railway and bus PT services is one of the main goals of the Master Plan for Integrated Passenger Transport [33].

Table 2. Number of departures of local buses from the Ludbreg stop to the surrounding municipalities during the working day, during the school year, showing the number of departures per hour.

	Number of Departures per Hour–Situation from 2022
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Ludbreg-Mali Bukovec	0	0	0	0	1	0	1	0	1	0	1	1	0	0	0	0	1	0	0	0
Ludbreg-Veliki Bukovec	0	0	0	0	1	0	1	0	1	0	1	1	0	0	0	0	0	0	0	0
Ludbreg-Sveti Đurđ	0	0	0	0	1	0	1	0	1	0	1	1	0	0	0	0	0	0	0	0
Ludbreg-Martijanec	1	1	1	1	0	1	0	0	1	1	0	0	1	1	0	0	1	0	0	0
	Number of departures per hour–Master plan standard to be achieved by 2027
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Ludbreg-Mali Bukovec	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Ludbreg-Veliki Bukovec	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Ludbreg-Sveti Đurđ	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Ludbreg-Martijanec	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
	Number of departures per hour–Situation from 2022
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Mali Bukovec-Ludbreg	0	1	1	0	1	0	0	1	0	0	0	0	1	0	0	0	0	0	0	0
Veliki Bukovec-Ludbreg	0	1	1	0	1	0	0	1	0	0	0	0	1	0	0	0	0	0	0	0
Sveti Đurđ-Ludbreg	0	0	2	0	0	0	0	1	0	1	0	0	0	0	0	0	0	0	0	0
Martijanec-Ludbreg	0	1	1	0	1	0	2	0	1	2	1	1	0	0	0	1	1	0	1	0
	Number of departures per hour–Master plan standard to be achieved by 2027
	4 to 5	5 to 6	6 to 7	7 to 8	8 to 9	9 to 10	10 to 11	11 to 12	12 to 13	13 to 14	14 to 15	15 to 16	16 to 17	17 to 18	18 to 19	19 to 20	20 to 21	21 to 22	22 to 23	23 to 0
Mali Bukovec-Ludbreg	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Veliki Bukovec-Ludbreg	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Sveti Đurđ-Ludbreg	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1
Martijanec-Ludbreg	0	1	2	2	2	1	1	1	1	2	2	2	2	1	1	1	1	1	1	1

Legend: red cell—no departures during that hour, light green cell—one departure per hour, dark green—two or more departures per hour. Source: [9,33].

shows the analyses of the number of departures from the Ludbreg main bus stop to the four settlements, which are all municipal seats of the surrounding municipalities. In particular, these municipal seats are: Martijanec, Sveti Đurđ, Veliki Bukovec, and Mali Bukovec. Table 2 also presents a comparison between the PT offer from 2022 and the standard offer foreseen by the Master Plan for Integrated Passenger Transport [33].

Table 2 clearly shows that the number of connections by public bus transport on a workday to other surrounding municipalities is poor. Departures to Ludbreg are mainly present during morning peak hours, and departures from Ludbreg are available during early afternoon peak hours. Possibilities to use PT during late afternoons and evenings are non-existent. The possibilities are even lower at weekends and holidays. The exception is the municipality of Martijanec, which also has a train connection with Ludbreg. These connections were already analysed in Table 1. Martijanec is a railway stop in the direction of Varaždin.

Table 2 offers a comparison of the offer recorded in 2022 with the standard set by Masterplan for Integrated Passenger Transport [33]. The Master Plan foresees that all the seats of municipalities and all the towns and cities in Varaždin, Koprivnica-Križevci, and Međimurje Counties are connected via direct lines or by connections, every 30 min during peak hours and every 60 min in the off-peak periods on workdays. The 2022 offer represented less than 20% of the goals outlined in the Master Plan, which were planned to be reached by 2027.

4.2. Tariffs Analysis and the Price of Transportation

An analysis of the tariffs in the Ludbreg area concluded that the ticket prices were not sufficiently attractive to attract more passengers.

The ticket prices shown in

Table 3. The prices of the single and monthly railway tickets in the area of Ludbreg in 2022 and 2023.

	Connection	Distance in Kilometres	Price for Single Ticket	Price for Monthly Ticket for Adults	Price for Monthly Ticket for Pupils and Students
Primary catchment area	Luidbreg–Čukovec	5 km	€1.15	€28.26	€19.64
	Ludbreg–Martijanec	6 km	€1.32	€35.44	€24.54
	Martijanec–Čukovec	11 km	€1.48	€42.46	€29.46
Secondary catchment area	Ludbreg–Varaždin	23 km	€1.81	€49.64	€34.38
	Ludbreg–Koprivnica	19 km	€1.63	€58.80	€39.14

Source: [9,37].

show affordable prices for traveling by train. Unfortunately, the railway infrastructure and passenger services do not reach most of the area that gravitates to Ludbreg, meaning most of the surrounding settlements are not in the vicinity of the railway infrastructure, railway stations, and stops. HŽ Passenger Transport Ltd. has a destination tariff system, meaning that tickets are only valid for a specific route between two stations or stops and cannot be used for travel within a particular tariff zone [37].

For more favourable rail trips, in addition to the discount on online ticket purchases, reasonable prices are available for all full-time students enrolled in the academic year 2024/2025. Namely, this year, the Government of the Republic of Croatia continues the pilot project of a more favourable transportation system for students, which, at a monthly ticket price of EUR 9.95, enables unlimited use of railway transport. The pilot project is conducted from 1 October 2022. It is based on unlimited daily travellers of train from place of residence to the place of study, including occasional trips, such as 1-day trips, going to the doctor, for holidays, and some other trips in the second class of regular trains in the Republic of Croatia [38].

Autobusni prijevoz Ltd., from Varaždin, Croatia, is a local private bus company that offers the service of the County passenger bus public transport in Varaždin County, including the city of Ludbreg and its surrounding areas. The prices of tickets range from EUR 2.10 to EUR 3.00, also depending on the route. Monthly tickets or monthly passes range from EUR 92.40 to EUR 132. The Ministry of Science, Education, and Youth of the Republic of Croatia covers 75% of the monthly ticket; pupils pay EUR 13.30 per month, while Varaždin County covers the rest of the amount. Students do not have discounts on bus tickets.

4.3. Modal Share of Passenger Transport and Preferences Towards Public Transport

The survey among citizens of the Ludbreg region provided insight into current mobility patterns and also revealed citizens’ preferences for using modern, integrated, and efficient public transport. During the survey, which was conducted in May 2022, an overall number of 313 valid questionnaires were collected.

The survey showed, as presented in

Table 4. The main settlements to which citizens of the city of Ludbreg and surrounding municipalities commute.

City/Settlement	Percentage of Commuters
Ludbreg	38.3%
Varaždin	12.1%
Veliki Bukovec	9.2%
Sveti Đurđ	7.1%
Mali Bukovec	6.7%
Zagreb	5.8%
Koprivnica	4.6%
Other	16.2%

Source: made by authors according to [9].

, that most of the people from the Ludbreg microregion travel to Ludbreg, which is the biggest and most important settlement in the region. The next city of big attraction is Varaždin, which is the seat of the County and the biggest city in Northern Croatia. The rest of the population travels to work, school, or the university to other seats of the municipalities, meaning Veliki Bukovec, Sveti Đurđ, and Mali Bukovec. A small number of commuters travel to Zagreb, the Croatian capital, and Koprivnica, the seat of the neighbouring County of Koprivnica-Križevci, while the rest of 16.2% of commuters travel to other destinations.

Most citizens travel to work, college, or school by car, 66.4% of them as drivers or passengers. Public transportation is represented by 13% (train and/or bus), and unmotorized modes, including hiking and cycling, at 17.8%.

The overall modal share, presented in Figure 1, shows a high dominance of car travel in the Ludbreg region.

The graph in Figure 1 clearly indicates the dominance of car travel in the Ludbreg region. Public transport and non-motorised modes make up less than 20% combined.

Further research on citizens’ preferences has shown that 2/3 want to use quality public transport for passengers, or 67.6% of them. In addition, 17.6% of citizens declared that they would maybe use quality public transport. The results are presented in Figure 2.

As for the extent to which citizens would use quality public transport service, 74.2% of citizens have stated that they would use quality public transport equally or more than their cars. The precise data can be found in

Table 5. Preferences for using quality public transport instead of a personal car.

Described Level of Public Transport Use Compared to Car Usage	Percentage of the Citizens
I would only use public transport, not a personal car	16.3%
I would almost always use public transport, not a personal car	30.4%
I would use public transport slightly more than a personal car	13.4%
I would use public transport equally to a personal car	14.1%
I would still travel mostly by a personal car, rarely by public transport	16.0%
I would not use public transport at all	9.8%

Source: [9].

.

The counting of passengers in rail transport was carried out at the Ludbreg railway station during the period of May 2022, during a workday. Passengers who entered and exited all passenger trains during the workday were included in the count. The overall number of people who travel by train was 548.

At the main bus stop in Ludbreg, the number of passengers, people who entered or exited buses, was 275. This passenger count was also conducted during a workday. In total, over 800 people travel by public transport on a daily basis, on workdays.

5. Proposal for a New Operational Concept for the Network of Public Passenger Transport Lines

A well-developed public transport system, through its operation and reliability, provides citizens and consequently the economy with a great number of direct and indirect positive effects that can be quantified [31].

An area with a quality public transport service provides citizens with a higher quality of life and provides all businesses with opportunities for better business. A quality public transport system, through its functioning and the ability for citizens, and thus the economy, to rely on its efficiency, brings a large amount of positive direct and indirect effects to the economy and society that can be calculated [39]. On the other hand, citizens who do not have adequate access to mobility, including public transport systems, can become socially excluded because access to employment and social activities may become partially or completely inaccessible to them [32]. In terms of the use of space, especially urban space, all sustainable modes, and here we primarily mean walking, cycling, and public transport modes, achieve significant advantages compared to individual car transport. These advantages are reflected in the transport capacity for the same width of a traffic lane or some other traffic or urban area, and in the problems related to car parking.

As an answer to the citizens’ surveys and the sustainable mobility needs of Ludbreg and its surrounding municipalities, three versions of the public transport networks were proposed. They were all designed to be used with an integrated clock-face timetable or pulse timetable.

To ensure the full sustainability of the new city bus network, the city plans to acquire five new electric buses, while additional diesel buses will be acquired as reserve vehicles and used when electric vehicles are undergoing maintenance [8].

5.1. Integrated Clock-Face Timetable, Pulse Timetable, or Cyclic Timetable

Public transport, in combination with walking and cycling, should become the dominant mode of travel for citizens in the city of Ludbreg and the wider region following the analysis of the 2022 Study, which created the basis for the long-term development potential of the city itself and its wider area. Integrated passenger transport, sometimes also Integrated Public Passenger Transport, is a local public transport system that combines different modes of public transport into a single unit in an area [33].

Such a system uses the advantages of all transport modes in the system, and through the cooperation of modes, it largely eliminates the disadvantages of a single mode of transport. It enables the creation of intermodal terminals, or places where it is easy to transfer from one transport mode to another, the coordination of timetables between different modes, and the use of single transport tickets for all types of modes in the system [33]. The concept of integrated passenger transport was developed by transport operators themselves, i.e., experts in public transport and mobility, who recognized the need for a more efficient and competitive system. The need arose in response to the increasing use of private cars. The first local integrated transport system in the world was founded in 1965 in Hamburg, Germany. Joint tariffs and timetable coordination were then contractually established by four independent companies. For the first time, users could transfer between trains, underground trains, buses, and boats in the Hamburg region with a single ticket [40].

The new network of lines is based on the principle of an integrated clock-face timetable, meaning that the departure intervals in the same direction are set to a constant value (time interval), depending on transport demand levels, vehicle capacity, and similar factors [41]. The integrated clock-face timetable is characterized by structured, identical planned time intervals for subsequent services. Services are periodic, with a precisely determined and equal time gap between them. Theoretically, the time intervals do not have to be the same for different services, but to utilize the systematic benefits of periodic scheduling fully, intervals are usually equal or integer multiples of a base time period. The period or time interval can take any value, and for regular and consecutive public transport services, it reflects either the total travel time on a route or an integer portion of it. Where possible, departures can be scheduled at round-number intervals, such as every 60 min. In this case, passengers only need to remember the departure minute; for example, 12 if trains from City X depart at 7:12, 8:12, 9:12, etc. [42]. Some authors call integrated clock-face timetable system by different names, but they can be considered as synonyms. For example, Hansen and Pachl call it cyclic timetable [23] and Vuchic calls it pulse timetable [19].

A cyclic timetable is based on a traffic pattern that repeats itself every hour. Within this pattern, trains (or buses, or other passenger local and regional modes) of the same route are scheduled at fixed intervals. Cyclic timetables are very common on European passenger lines for commercial reasons. Some railways (or operators in other modes) with an extensive passenger operation have connected the cyclic timetables of different routes of the network. In such an integrated cyclic timetable, trains (or other local and regional modes) on different routes are scheduled in a way that, in a connecting terminal, all trains always meet at the same time to enable the passengers to change between all lines [23]. The example of an integrated cyclic timetable can be seen in Figure 3.

The application of an integrated clock-face timetable enables easy transfers for passengers at key transport hubs (provided that all necessary infrastructure conditions are met), while connections between different lines and modes allow users to continue their journey to their final destination. If combined with a Transit-Oriented Development (TOD) approach, integrating walking-public transport-walking travel options, the system ensures high regional accessibility and significantly enhances the attractiveness of public transport. The time of departure and arrival of trains at the final hub stations at regular time intervals is called tact running time. The specific scheduling interval depends on transport needs and the number of passengers on a given route [9]. The integrated clock-face timetable is also called a Pulse timetable [19,20,21,22] and has already been conceptually applied in other cities in Northern Croatia, such as Varaždin, where similar regional mobility challenges were addressed using this model [29].

A clock-face timetable aims to synchronize all lines at a single hub so that they depart at approximately the same time. This means that railway traffic should be organized so that all trains from different directions serve key railway hubs around the same time. At these railway hubs, trains from all directions converge at regular intervals, offering passengers multiple options for onward travel immediately upon arrival. A clock-face timetable increases the speed of travel within the network, reducing waiting times for transfers [9]. An example of transfers between two feeder lines and a mainline is also shown in Figure 3.

Due to the implementation of an integrated timetable, all transfers between all lines can be repeated at regular time intervals. Such a system enables the continuous repetition of times throughout the day when all vehicles from all lines passing through a hub actually stop at the hub for a few planned minutes. This ensures that passengers can transfer from one line to any other line. By enabling transfers at key hubs through the application of a clock-face timetable, passengers can reach any destination (station or stop) within the system.

Therefore, the integrated clock-face timetable system ensures complete spatial and temporal accessibility across the entire region where it is implemented [9].

5.2. Integrated Public Transport Concept and Schematic Public Transport Map—First Variant

The scheme of the local public transport network for the area of Ludbreg and surrounding municipalities covers the primary scope of the Study of the Development of a Sustainable Public Transport System and a Non-Motorized Mobility System for the City of Ludbreg and the Municipalities of Martijanec, Sveti Đurđ, Veliki Bukovec, and Mali Bukovec [9]. The scheme is designed to allow users to easily plan their journey using only the map. The scheme is designed to be used with an integrated clock-face timetable or pulse, or cyclic timetable.

The first variant was designed with five lines and covers the area of the city of Ludbreg and the municipalities of Mali Bukovec, Veliki Bukovec, Sveti Đurđ, and Martijanec, as can be seen in Figure 4.

Each line in the system has a uniquely assigned number and color for easy recognition and clear distinction. In addition to the five bus lines, marked with numbers 1 to 5, a suburban railway line is also shown. The railway line R202, Varaždin—Dalj, passes through this area, and it is planned to be part of the suburban railway system of the Northern Croatia region in the future.

The system is designed so that all lines meet at a key hub, the future Ludbreg Centar bus station, next to which it is planned to build a new Ludbreg Centar railway station. This will enable easy passenger transfers between road public scheduled passenger transport and rail passenger transport, which, together with the synchronization of timetables and the application of a common fare (a common transport ticket for train and bus), will enable the development of integrated passenger transport in the area.

An integrated clock-face timetable, also known as a pulse or cyclic timetable, was designed for the system. On every line, every bus comes to the main bus terminal at full hour and leaves at full hour and 7 min. The first arrival is at 6:00, and the first departure is at 6:07. The last arrival of the day with a connection is at 20:00, and the last departure is at 20:07. The last line arrives at the main terminal at 21:00. There is a pause in the service from 9:00 to 10:07 and 17:00 to 18:07. These breaks are predicted for drivers to have their mandatory pause. Also, these breaks can be used to charge the buses with electric energy so they can cover their daily routes [8].

5.3. Integrated Public Transport Concept and Schematic Public Transport Map—Second Variant, City of Ludbreg Only

This version shows a system that covers only the area of the city of Ludbreg, meaning all settlements in the area of the city of Ludbreg. This variant was designed to explore the possibilities of running the city bus network in Ludbreg only, in case the surrounding municipalities are not ready to join the city’s public transport system. The network of lines planned for this variant is shown in Figure 5.

The network was created according to the previously mentioned methodologies, but the geographical scope was smaller. Each line here also has a uniquely assigned number and colour for easier recognition and clear distinction. In addition to the five bus lines, marked with numbers from 1 to 5, a suburban railway line is also shown.

An integrated clock-face timetable, also known as a pulse or cyclic timetable, was designed for this variant of the system. On every line, every bus comes to the main bus terminal at full hour and leaves at full hour and seven minutes. The first arrival is 6:00, first departure is at 6:07. The last arrival of the day with the connection is at 20:00, and the last departure is at 20:07. The last line arrives at the main terminal at 21:00. There is a pause in the service from 9:00 to 10:07 h and from 17:00 to 18:07. These breaks are predicted for drivers to have their mandatory pause. Also, these breaks can be used to charge the buses with electric energy so they can cover their daily routes [8].

5.4. Integrated Public Transport Concept and Schematic Public Transport Map—Third Variant—Combination

The third variant of the proposed network is a combination of the previous two systems. Although the routes cover the surrounding municipalities, the routing of the lines was designed to cover more settlements in the area of the city of Ludbreg. Although this variant offers the longest travel times among all the variants, it also provides the best accessibility and the most comprehensive coverage of the region.

Figure 6 shows the third proposed variant for the network of lines for municipal local bus passenger transport in the primary study area. The network was created according to the previously mentioned methodologies. Each line in the system has a uniquely assigned number and color for easier recognition and clear distinction. In addition to the five bus lines, marked with numbers from 1 to 5, a suburban railway line is also shown. The railway line R202, Varaždin—Dalj, passes through this area, and it is planned that it will be part of the suburban railway system of the Northern Croatia region in the future, too.

An integrated clock-face timetable, also known as a pulse or cyclic timetable, was designed for this variant of the system as well. On every line, every bus comes to the main bus terminal at full hour and leaves at full hour and 7 min. The first arrival is 6:00, the first departure is at 6:07. The last arrival of the day with the connection is at 20:00, and the last departure is at 20:07. The last line arrives at the main terminal at 21:00. There is a pause in the service from 9:00 to 10:07, and from 17:00 to 18:07. These breaks are predicted for drivers to have their mandatory pause. Also, these breaks can be used to charge the buses with electric energy so they can cover their daily routes [8].

5.5. Total Costs, Incomes, Tariffs, and the Promotional Activities to Increase Ridership

Total costs, tariffs, and promotional activities are being elaborated shortly.

Due to a minimal number of average daily kilometres per vehicle in the system, the method of bus/day overall costs was used to calculate the yearly costs of the system. The bus/day price is taken from the Study Minimum Standards of Accessibility in Public Passenger Transport in Road Transport in the Republic of Croatia for M3 category buses that operate for at least 360 days a year and travel over 600 km per day [43]. The overall costs for the entire year amount to EUR 911,441.50. It was predicted that the income from ticket sales would cover up to 15% of the overall costs in the 1st year [8]. It was also predicted that the share of incomes in the overall costs will rise through the years, but it is expected that most of the costs will still be covered from the budget of the City of Ludbreg and the surrounding municipalities. It is also expected that all three proposed variants of the public transport system will create similar overall costs, except for the second variant, where the overall cost might be lower than the presented figure due to a much smaller number of average daily kilometres compared to the other two variants.

The attractiveness of the public transportation system depends on its financial accessibility. It is particularly important that seasonal tickets, especially monthly and annual tickets, are affordable. It is also always necessary to take into account that the prices of season tickets are significantly lower than the sum of potential individual trips for that period in order to make it easier for citizens to decide and bind themselves to the system by purchasing long-term season tickets.

It is proposed that transport tickets can be purchased at bus station ticket offices, public administration offices, and tourist board offices, and from bus drivers and retail stores. In addition to the use of paper transport tickets, it is certainly recommended to develop the use of smart cards for public transport, and the possibility of purchasing on the website or via a mobile application [8,9]. The proposed tariff system was based on just one tariff zone for the entire region of the public transport system. The proposal is presented in

Table 6. Tariff system proposed for a new urban public transport for the city of Ludbreg and the surrounding municipalities.

Name/Type of the PT Ticket	Price for Pupils and Students	Price for the Retired and Other Social Categories	Price for Citizens/Working Population	Valid to	Remark
Single ticket	EUR 0.40	EUR 0.40	EUR 0.50	Valid for 90 min	Valid for unlimited number of rides and transfers during the time of its validity.
Daily pass	EUR 1.10	EUR 1.10	EUR 1.40	Valid for the entire day on the day of validation.	Valid for unlimited number of rides and transfers during the time of its validity.
3-day pass	EUR 2.10	EUR 2.10	EUR 2.40	Valid for unlimited number of rides for the day it was validated and two more following full days.	Valid for unlimited number of rides and transfers during the time of its validity.
Monthly pass	EUR 9.50	EUR 9.50	EUR 1.50	Valid for unlimited number of rides for 30 days from the day it was issued.	Valid for unlimited number of rides and transfers during the time of its validity.
For all the tickets purchased online and via mobile application, a 10% discount is applied.

Source: made by authors according to [44].

.

The implementation of the above measures can lead to a significant amount of revenue, with, of course, the implementation of additional measures [8,9]:

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Promotional campaigns that encourage the use of public passenger transport, using various information channels (social networks),

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Creation of a printed and web database of information on how to use the public transport system, planning trips in the public transport system, and finding the appropriate type of transport tickets and passes,

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Educational campaigns that teach target groups in society, e.g., young people, students, retirees, and employees, about the advantages of the public transport system, and about how to use and plan trips in the public transport system,

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Educational and promotional campaigns for the youngest generations on how to safely use the public transport system (public organization of promotions and games for children, production of picture books, production of toys, production of colouring books, production of school supplies with elements of promotion of travel by public transport, etc.),

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Holding public forums and events that promote the use of the public transport system through media releases,

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Holding expert forums on the development of public transport systems and sustainable transport systems in general.

5.6. Research Limitations

Although the study provides valuable insights into the potential development of a public transport system in Ludbreg and the surrounding municipalities, several limitations need to be acknowledged. The survey sample, while valid for the purposes of this research, may not fully represent the diversity of all potential users, which introduces a degree of sampling bias. Furthermore, the financial aspect of the analysis was conducted on a general level without a detailed cost–benefit assessment that could provide a more comprehensive evaluation of long-term feasibility. In addition, the modeling of the system was limited in scope: detailed spatial analyses using GIS tools, such as accessibility of bus stops or coverage of the network, were not undertaken. Addressing these aspects in future research could help build a more precise picture of travel demand and the financial and spatial performance of different development scenarios for the public transport system.

6. Conclusions

This study has analysed the proposals for a network of lines for the city and local public transport system. The first proposed version of the network covers the city of Ludbreg and surrounding municipalities but does not include certain potential stops within the city itself. The second version focuses exclusively on the administrative area of the city of Ludbreg, and the proposed five lines cover almost all urban settlements. The third version represents a combination of the first two, offering the most extensive coverage of both urban and surrounding areas. The implementation of a high-quality public passenger transport system is expected to generate positive effects on the environment, local economy, and overall quality of life for residents.

The current modal share of private car use in Ludbreg and the surrounding municipalities is very high, accounting for 81% of all passenger kilometres. To reduce such a high level of car dependency and to improve the quality of life in the region, the introduction of an integrated and efficient public transport system is necessary. In recent years, the level of service in public transport has remained at approximately 20% of the standard set by the Master Plan for Integrated Passenger Transport—the regional transport strategy for Northern Croatia from 2017 to 2027.

A population survey conducted in Ludbreg and surrounding municipalities indicates a strong preference for a high-quality public transport system. A total of 68% of respondents stated that they would use frequent and well-coordinated local public transport with synchronised timetables and guaranteed transfers between local lines, as well as with regional buses and trains. An additional 18% expressed a potential interest in using such a system. The survey further revealed that most travel demand is oriented toward Ludbreg itself, both for daily commuting and for other occasional purposes beyond work and education.

Although this study does not include a formal cost–benefit analysis, it is possible to assess the justification for the proposed public transport system through a basic comparison of anticipated benefits and estimated operational costs. According to available data, the annual operating cost of the system is approximately EUR 911,441.50 [8], with expectations that up to 15% of this cost will be covered by ticket revenues during the initial years of implementation. The expected benefits span several dimensions. On a social level, the system improves access for students, older adults, residents without private vehicles, and those living in less connected settlements. Economically, better public transport supports access to employment, education, and services, potentially reducing household transport costs and supporting local development. Environmentally, the introduction of regular and synchronised public transport, alongside the planned use of electric buses, could lead to a reduction in carbon emissions, noise, and road congestion.

Preliminary estimates suggest that reducing car use by 8–10% could result in annual CO₂ savings of more than 1000 tonnes, contributing meaningfully to sustainable mobility targets at both local and regional levels. With increasing ridership and further promotional activities, the benefit-to-cost ratio is expected to improve over time. In this context, the proposed system can be regarded as a socially and environmentally justified investment that aligns with broader goals of sustainable development.

The developed public transport concepts were designed as an answer to the citizens’ needs and the citizens’ willingness to use sustainable, frequent, and high-quality public transport. The approaches developed in this study may also be applicable in other similar regions across Europe and beyond. In addition to implementing a local high-quality public transport system in Ludbreg and its surrounding municipalities, it is essential to continue supporting the development of integrated passenger transport throughout the entire region of Northern Croatia. Strategic documents at the local, county, national, and EU levels strongly encourage such initiatives.

Therefore, in parallel with the implementation of urban public transport in Ludbreg, coordinated efforts should be made to ensure that comprehensive, reliable public transport services are developed across the region.