Smart Crosswalks for Advancing Road Safety in Urban Roads: Conceptualization and Evidence-Based Insights from Greek Incident Records

Abstract

Urban intersections are critical for pedestrian safety, as they usually account for high rates of traffic-related injury and fatalities. This study assesses smart crosswalks as an alternative approach to improve road safety that is inherently aligned with the development of intelligent transportation system technology. After a brief background on this technological advance, this study proceeds with the analysis of long-term crash records from Greek urban roads, concentrating on pedestrians’ behavior in incidents involving road crossing. Thereafter, challenges related to the adoption of an implementation framework are identified. The results confirmed the vulnerability of pedestrians, especially during cases with no specific crossing areas, based on a considerable number of available recorded crashes from a publicly available Greek database. Substantial reductions over the analysis period (i.e., years 2005–2022) in pedestrian-based incidents with injuries and fatalities at a rate of 44% and 52%, respectively, provide evidence-based insights that infrastructural interventions like improved crosswalk design can be translated into measurable benefits for pedestrian safety. Key factors toward a wider applicability framework for even safer interventions through smart crosswalks include maintenance strategies, user education, and systematic integration of funding into urban mobility plans.

1. Introduction

1.1. Technological Innovations in Road Safety

On a worldwide scale, numerous initiatives have been undertaken to minimize road crashes, which continue to pose a major challenge to the advancement of road transportation systems. Each year, approximately 1.19 million fatalities are attributed to road traffic incidents globally [1], leading to substantial economic and societal burdens for communities. For example, the financial impact of road traffic fatalities is estimated to range from one to three percent of a country’s Gross Domestic Product (GDP) [1]. Even in highly developed nations, the toll of injuries and deaths remains notably high. Consequently, enhancing the safety of road infrastructure remains a key priority for both communities and policymakers [2].

Among various elements of road networks, urban roadways are known to face a considerable number of incidents. Intersections are particularly critical in managing urban mobility, as they support the orderly and secure flow of vehicles, cyclists, and pedestrians, especially in areas of crosswalks. Nevertheless, intersections are frequently associated with a high incidence of crashes, particularly in city environments. As reported by the American Automobile Association (AAA) Foundation for Traffic Safety, approximately 39% of urban road traffic fatalities in the United States between 2010 and 2019 occurred at intersections [3,4].

At the same time, the swift pace of technological development and the introduction of innovative solutions in road environment have opened new avenues for designing more intelligent intersections aimed at improving safety and operational efficiency [5,6,7,8]. By harnessing the capabilities offered by smart technologies, these advanced road infrastructure elements have the potential to significantly contribute to sustainability, safety, innovation, and greater inclusivity. These intelligent infrastructures are envisioned to reshape the interaction between vehicles, users, and the surrounding road environment by incorporating cutting-edge technologies that could prove even more useful for the new era of autonomous vehicles (AVs) and connected and automated vehicles (CAVs).

Cooperative intelligent transportation systems (C-ITSs) are expected to support smooth communication between vehicles, infrastructure, and pedestrians. Beyond utilizing a wide array of sensors to monitor safety, performance, and environmental conditions, these infrastructures will also integrate supplementary technologies such as dedicated lanes for AVs/CAVs, Internet of Things (IoT)-enabled surveillance systems, and adaptive traffic control mechanisms. Real-time traffic operations at smart intersections will rely heavily on Transportation Management Systems, Data Analytics, and Vehicle-to-Everything (V2X) communication—core elements of intelligent transportation systems (ITSs)—which collectively advance sustainable urban mobility. By merging digital sensors with real-time traffic monitoring tools [9,10,11], these intersections surpass the capabilities of traditional designs (e.g., signal-controlled crossings).

Overall, the rapid evolution of connected vehicle technologies and artificial intelligence (AI)-based traffic management strategies in support of urban sustainability initiatives has positioned smart intersections as key nodes in next-generation transportation networks [3,12,13]. However, much of the current literature still focuses on standalone technological solutions, such as adaptive signal controls and challenges in coordinating CAVs.

1.2. Pedestrian Vulnerability: The Role of Safer Intersections

The presence of pedestrians is an inherent aspect of urban road environments irrespective of the presence of conventional vehicles or AVs. Urban intersections represent convergence points for both vehicular and pedestrian traffic, making them high-risk zones for crashes. Statistical data indicates that over 60% of traffic collisions occur at these junctions, with approximately 90% happening during traffic signal transitions [14]. Related research has shown that when pedestrians begin crossing within the final five seconds of a green signal phase, most are unable to finish crossing before the red light is activated [15]. Consequently, during these transitional moments, pedestrians often remain in the intersection while vehicles, having gained the right-of-way, begin moving—a condition that leads to dangerous conflicts that can further result in crashes.

Therefore, it is justifiable that among all road users, pedestrians are the most prevalent, widely dispersed, and vulnerable group in transportation systems [16]. Reports indicate that pedestrian casualties account for more than 20% of traffic-related injuries, with over half occurring during crossing maneuvers [17]. These findings underscore the urgent need to improve pedestrian safety, particularly during signal transitions at urban intersections [18].

Among the various strategies intended to enhance road safety, increasing emphasis is being placed on protecting the most vulnerable road users—pedestrians. In the realm of vehicle design, well-established approaches include (i) modification of the hood geometry of the front and end edge of the vehicle (i.e., adjusting height, curvature, and overall vehicle profile) to eliminate sharp edges and reduce impact severity, and (ii) implementation of external airbags specifically for pedestrian impact mitigation. While these measures are designed to minimize injury severity during collisions, the primary goal should be to prevent such incidents from occurring in the first place [18].

As noted in [16,18], key challenges in road traffic safety stem from risky behavior by road users, substandard road infrastructure, and the absence of an effective traffic safety management system. One potential response to these issues involves upgrading and modernizing existing crosswalks, which can enhance overall experience and safety for both pedestrians and drivers. According to [14,18], crosswalks rank as the second most frequent sites of road crashes, following roadways themselves. This highlights the critical need to deploy innovative solutions, particularly at locations where pedestrian and vehicular traffic intersect [19].

Marking pedestrian crosswalks at intersections often instills in pedestrians a sense of visibility to motorists—an assurance that is unfortunately not always justified—thereby increasing pedestrian confidence in utilizing these designated areas [20]. The deployment of continuously flashing lights at crosswalks has gained popularity as a safety measure. However, it has been noted that the persistent use of yellow pulsating lights may induce a hazardous effect, whereby drivers become desensitized to such signals, leading to diminished attention and slower reaction times when pedestrians enter the crossing zone. Consequently, this situation creates a dual risk: pedestrians may harbor an unfounded belief in their safety and thus be more inclined to use marked crossings, while drivers’ habituation to constant flashing lights may compromise their vigilance, potentially resulting in dangerous traffic incidents [21].

Therefore, pedestrian safety still remains a critical concern in the broader context of road traffic safety, with pedestrians accounting for more than 20% of global road traffic fatalities [21,22]. Unsignalized pedestrian crosswalks are especially perilous, particularly in environments characterized by high pedestrian volumes, elevated vehicle speeds, and limited sight distances—conditions that would typically warrant signalization yet often remain uncontrolled in practice because of multi-scale factors. Even where warning signage exists, drivers may fail to adapt speed appropriately, thereby elevating crash risk. To mitigate these hazards, traffic authorities have introduced various safety interventions including road narrowing, traffic-calming features near crosswalks, and the implementation of smart crosswalks equipped with responsive warning lights activated by pedestrian presence [5,21]. Moreover, empirical evidence indicates that modern roundabouts can significantly reduce pedestrian crash rates by lowering vehicle speeds and eliminating conflicting traffic phases [7,8].

Additional research within the domain of driver–pedestrian interactions has explored aspects such as driver behavior [23], pedestrian crossing speeds [24], and the dynamic interactions between drivers and pedestrians at crosswalks [25,26]. Previous investigations have primarily concentrated on assessing the efficacy of safety measures designed to improve pedestrian protection [27]. Empirical evidence suggests that flashing warning signals and supplemental lighting positively influence driver behavior [28]. Moreover, the integration of LED curb lighting with flashing indicators has demonstrated effectiveness in enhancing pedestrian visibility and improving driver reaction [29,30,31].

Ultimately, it can be said that the incorporation of advanced smart technologies over the past few years within urban infrastructure has fundamentally altered perspectives on mobility and traffic safety. Smart crosswalks, i.e., innovative systems designed not only to enhance pedestrian safety but also to support the wider development of intelligent transportation frameworks, are definitively an illustrative example of smart technology applications.

1.3. Aim and Objectives

On these grounds, the aim of the present study is to evaluate the potential of smart crosswalks in the context of urban environments and assess critical issues regarding their implementation so that pedestrian safety can be further enhanced. Most existing studies either examine the technological aspects of smart crosswalks (e.g., sensor systems) or analyze pedestrian-related incident statistics, but they rarely integrate both perspectives. Thus, the research gap that this study wishes to bridge includes the joint consideration of evidence-based, long-term data from Greek incident records at crosswalk areas with the main implementation and feasibility challenges of a typical smart crosswalk. To meet the research aim, the following objectives were set:

• To present the main architecture, components, and key issues related to the technology of smart crosswalks based on the implementation knowledge so far;
• To assess records of road incidents with pedestrians in urban road networks from the Greek territory over a long analysis period;
• To highlight the need for a deployment framework by identifying key challenges and future opportunities for this emerging technology, based on quantifiable improvements in pedestrian safety derived from the analyzed data.

Ultimately, the contribution of this study is to synthesize evidence from empirical data with practical framework evaluation and underscore the pressing needs to prioritize the implementation of safe and intelligent crosswalk technology in the broader context of a smart city environment.

2. Smart Crosswalk Technology: Architecture and Components

2.1. Basic Design of an Active Smart Crosswalk

2.1.1. Core Elements

As cities continue to grow, smart crosswalk technology offers not just safer streets but a smarter, more connected urban future. Architecture and components of smart crosswalks may vary, depending on the needs of the specific road intersection. However, a simple design may be more effective in terms of functionality and in case of maintenance needs. A typical design of a smart crosswalk is presented in Figure 1.

The main components include the following:

• Warning D-6 Sign: The warning signaling system is a core element of a smart crosswalk, automatically triggered upon pedestrian detection. It typically involves activating pulsating yellow lights to alert drivers for the presence of pedestrians at the crosswalk. With advanced signaling technologies, the system can also adjust the duration of warnings based on prevailing conditions. Also, the D-6 sign can be illuminated during the night to help both pedestrians and drivers notice the exact location of the crosswalk.
• Plough-Resistant Active Road Studs: These are active spot retroreflectors mounted at least in front of each conditional stop line or in both sides of the crosswalk. They are double-sided with yellow warning LEDs. The shape of the spot retroreflectors ensures smooth passage of vehicles. They are activated when a pedestrian is detected. The active retroreflector is made of high-impact, clear polyethylene with IP68 protection [32]. The insert is equipped with three LEDs for each direction—from the oncoming side and from the horizontal marking side. The bodies of the retroreflectors are permanently placed in the abrasive layer of the roadway, and the active elements are connected by cables covered with roadway filler.
• Audio for Visually Impaired Pedestrians: The audio system for visually impaired pedestrians emits directional acoustic signals—typically pulsed tones or voice messages—synchronized with pedestrian phases of the traffic signal. Activated via push-button, sensor input, or remote trigger, it provides real-time feedback on signal status and crossing initiation. Integrated with tactile indicators and accessibility standards, it enhances spatial orientation and crossing safety in complex urban environments.
• Motion Sensors: A motion sensor detects pedestrian movement near or on a crosswalk using infrared or microwave signals. When motion is identified, the sensor activates the crossing system—triggering lights, alerts, or vehicle warnings. This enhances visibility and response time, ensuring safer pedestrian passage, especially in low-visibility or high-traffic conditions.
• Control Cabinet: The control cabinet houses the core electronic components that manage smart crosswalk systems. It integrates power supply units, communication modules, signal controllers, and input/output interfaces for sensors, lighting, and audio devices. Designed for outdoor environments, it features weatherproof enclosures, surge protection, and remote diagnostics to ensure reliable, continuous system operation.
• Solar-Powered Smart Lighting: This system utilizes high-efficiency photovoltaic panels to power LED-based illumination at crosswalks. It includes integrated solar charge controllers, energy storage units, and automatic brightness adjustment based on ambient light or pedestrian detection. Designed for autonomous operation, it enhances crosswalk visibility without requiring grid connectivity, supporting sustainable and low-maintenance infrastructure deployment.
• High-Friction Surface: The implementation of high-friction, anti-slip surface coatings at crosswalks is intended to improve safety by minimizing the risk of vehicle skidding—particularly in areas where vehicles approach at higher speeds. By increasing surface traction, these treatments significantly reduce stopping distances under variable weather and road conditions, thereby enhancing drivers’ ability to respond in time and protect crossing pedestrians. Drivers can probably perceive high-friction surfaces as being rougher, but the increase in surface friction coefficient is much more prevailing. To improve tire–road interaction, it is a common international practice to improve skid resistance through specialty sealing applications, thermosetting resin binders, including epoxy- and polyurethane-modified binders, and other forms of polyester and resin esters in combination with appropriate aggregates, i.e., type and gradation [33].

Figure 2 illustrates some additional smart crosswalk features that complement those shown in Figure 1, and may include the following:

• Embedded Anti-Parking Pavement Sensor: The embedded anti-parking pavement sensor is installed directly within the road surface to detect and prevent unauthorized vehicle stopping or parking. It operates through magnetic, infrared, or pressure-based detection, sending real-time signals to control systems or warning devices. Designed with durable, weather-resistant housing, it ensures continuous monitoring and contributes to safer, obstruction-free crosswalk and traffic flow.
• Self-Illuminated Traffic Sign with Additional Retroreflective Surface: The self-illuminated traffic sign combines active LED-based lighting with a retroreflective surface to ensure maximum visibility under varying environmental conditions. In compliance with relative traffic code regulations, the integrated illumination enhances recognition at night or during low-light scenarios, while the retroreflective layer guarantees visibility when external light sources, such as vehicle headlights, are present. This dual system significantly improves driver awareness and pedestrian safety near crosswalks.

In other words, smart crosswalks are advanced systems that may combine infrastructure components and detection technologies to improve pedestrian or cyclist safety. Key features—such as high-friction (anti-slip) pavement surfaces, warning lights, reflective elements, motion sensors, and signaling systems—operate in synergy to enhance visibility, alert drivers and extend their response time to pedestrian/cyclist presence. The overall effectiveness of such systems relies heavily on proper design, calibration, and seamless integration with existing roadway infrastructure.

2.1.2. Infrastructure-Related Aspects

As shown in Figure 1, a typical smart crosswalk can include a specially treated anti-skid surface that aids driver deceleration just before the crosswalk. This effect can be achieved by replacing conventional asphalt with high-friction pavement surface, for instance, by incorporating rougher aggregate into the asphalt mixture. However, the implementation of high-friction pavement surface is not the unique factor that can affect the braking distance as it is influenced by several other factors too; the predominant factor is vehicle speed. According to [21,34], for a passenger vehicle moving on a dry surface, the total stopping distance from hazard detection is approximately 28.8 m at 50 km/h, increasing to 37.4 m at 60 km/h. Road surfaces with higher friction coefficients may significantly reduce the braking distances, thus improving the safety performance of the crosswalk [21,35].

In addition, it should be stressed that the occurrence of unfavorable weather conditions, rain, snow, or ice will reduce the vehicle’s grip and thus increase the braking distance. However, when a high-friction material is used for black-spot locations, such as a nearby crosswalk, increased anti-skid properties may be anticipated. Under the framework of a holistic road maintenance plan, the friction coefficient should be measured in specific periods throughout the year in order to plan maintenance actions well ahead [36]. For the case of crosswalks, where spotted friction measurements have to be collected, static measuring devices can be used, for instance the British Pendulum Tester (BPT). The BPT is a portable device with many advantages that can be used to check the level of friction coefficient in front of a crosswalk area, as well as on zebra-crossing markings.

In any case of high-friction material though, the speed of the vehicle that approaches a crosswalk is the crucial factor to avoid crashes. Hence, it is of utmost importance to effectively alert drivers that there is a crosswalk ahead. Drivers tend to focus more on elements that emit pulsating yellow light when approaching a crosswalk. Depending on the design variant, additional lighting behind the crosswalk area may appear as white, steady yellow, or pulsating yellow. However, the lack of clear guidelines or harmonized standards for installing active retroreflectors perpendicular to the traffic direction creates inconsistency in their placement. As a result, certain configurations may generate confusion and reduce drivers’ intuitive understanding of the road situation [21].

With the view of optimizing pedestrian visibility at crosswalks, advanced lighting systems are deployed within both the crossing zones and adjacent waiting areas. These systems utilize specialized directional luminaires that facilitate accurate situational awareness for both drivers and pedestrians. Another additional cutting-edge feature that can be used to enhance illumination is a selective pedestrian detection system, which integrates video analytics devices into the lighting infrastructure. Upon detecting a pedestrian’s presence, the embedded algorithm evaluates the object’s dimensions and dynamically adjusts the lighting intensity to enhance visibility at the crosswalk [3,10,21].

2.2. Integration of LED Technology: Installation and Operational Considerations

Building smart crosswalks involves much more than simply installing LED lights or motion sensors. A truly resilient system must be weather-resistant, built with durable, certified materials and designed in a modular way to allow for easy maintenance or rehabilitation [18].

Related studies, e.g., Saad et al. [37], and other case examples show how wireless components and standardized modular units can lower maintenance demands and extend the lifespan. Moreover, using certified LED studs—such as those compliant with EN124-D400—ensures they can endure heavy loads and harsh urban conditions. To maximize efficiency, modern systems are also being paired with predictive maintenance and seasonal adaptability features enabled by IoT technologies [37,38].

The integration of light-emitting diodes (LEDs) into road surfaces represents an innovative advancement in intelligent transportation systems. By embedding LEDs within the pavement structure—typically through specialized panels or modular units connected to a power source and control system—it is possible to create dynamic and customizable road markings, signage and safety features. Such systems enhance road visibility and adaptability, particularly under adverse weather conditions. Below, technical information regarding the usage of LED systems in smart crosswalks is presented [18,37].

2.2.1. Planning and Design

The initial phase involves a comprehensive assessment of the intended application of the LEDs, whether for delineating road lines, highlighting pedestrian crosswalks, conveying signage, or issuing hazard warnings. Appropriate selection of LEDs is critical, considering parameters such as brightness, color rendering, and long-term durability. System design must address the spatial layout of LED modules, their electrical wiring, and the control architecture. Environmental considerations—such as temperature fluctuations, moisture exposure, and mechanical stress because of vehicular traffic—must be incorporated to ensure sustained functionality and safety.

2.2.2. Materials and Components

The core components include the following:

• LED panels/modules: engineered to be embedded into the road surface and withstand external stressors.
• Wiring and connectors: weather-resistant, durable systems are required to ensure consistent power delivery and data transmission.
• Power source: a stable energy supply—either from the electrical grid or renewable sources such as solar panels—is essential.
• Control systems: these enable real-time modulation of LED brightness, color, and operational patterns in response to traffic or environmental inputs.

2.2.3. Installation Process

The implementation begins with precise excavation of the road surface to accommodate LED modules. Installation must ensure that the panels are flush with the pavement to maintain surface continuity and safety. This is conceptualized in Figure 3.

Electrical components are then connected to the power and control infrastructure, with all junctions properly sealed to prevent water ingress and corrosion. Final steps include system testing and calibration to verify operational integrity. In addition, road markings may be placed before the installation of the components.

2.2.4. Maintenance Requirements

Ongoing maintenance is vital to ensure long-term performance and safety. This includes the following:

• Regular inspections to detect wear, damage, or malfunction.
• Surface cleaning to maintain light visibility.
• Component replacement as needed to address any failures in LEDs or associated hardware.

2.2.5. Practical Applicability

Several real-world applications illustrate the potential of LED-integrated roads, including the following:

• Dynamic Road Markings: LEDs enable adaptive traffic management by changing lane directions or signaling hazards in real time.
• Enhanced Visibility: in fog, snow, or heavy rain, LEDs improve visual guidance, thereby enhancing road safety.

Related companies, e.g., ref. [39] have also invested in developing intelligent pavement systems using embedded LEDs for signage and lane guidance.

2.2.6. Key Considerations

Implementation must adhere to relevant safety regulations and construction standards [37]. While the upfront investment can be substantial, long-term benefits—including reduced maintenance costs, energy efficiency, and increased road safety—justify the expense. Ensuring correct installation and regular maintenance is imperative to guarantee the system’s reliability and the safety of both drivers and pedestrians.

3. Effectiveness of Smart Crosswalks

3.1. Detection Accuracy

Recent research evaluating the performance of smart pedestrian detection systems has demonstrated promising technical potential, while simultaneously identifying critical aspects that require additional focus to guarantee enhanced road safety [21,40].

A key finding highlights the high accuracy of pedestrian detection, with some systems achieving success rates up to 91.3% (Figure 4). This level of precision, equivalent to 274 correct activations out of 300 trials, emphasizes the capability of these technologies to reliably identify pedestrians intending to cross a road, thereby enhancing overall road safety. Furthermore, instances of false activations triggered by pedestrians merely in proximity to the crossing, but without the intention to cross, were exceedingly infrequent—only 5 out of 300 cases—indicating the advanced nature of the detection algorithms in accurately differentiating genuine crossing intent [21].

Equally noteworthy is the system’s effectiveness in minimizing false activations caused by vehicles. In particular, from 1000 detection attempts, only 7 instances were incorrectly triggered by passing automobiles. This indicates a high level of resilience to background traffic noise and irrelevant movement, which is essential for reliable operation in complex urban environments. Nevertheless, despite this strong performance, certain limitations have been identified in the trial experiments in ref. [21]. Specifically, missed activations—where the system failed to detect pedestrians attempting to cross—occurred in 7% of cases (21 out of 300 trials). Such omissions pose a significant safety risk by undermining system reliability and potentially exposing pedestrians to danger. These shortcomings underscore the necessity for improved sensor calibration and the development of more sophisticated detection algorithms [21].

3.2. System Limitations

Beyond technological challenges, driver behavior remains a critical obstacle. Field data reveal that only 27.8% of drivers (139 out of 500 vehicles) yielded to pedestrians at active crosswalks, even when alerted by the system [21]. Over 70% of drivers disregarded these warnings, highlighting the fact that infrastructure upgrades alone are insufficient. To maximize the effectiveness of smart crosswalks, complementary measures such as public education, stricter enforcement, and driver-focused technologies—including flashing signals, speed regulation devices, and in-vehicle alerts—are imperative [21].

The issue of cybersecurity should be considered from early stages during the design of smart crosswalks. In other words, aspects like device authentication, encrypted communications, secure endpoints, etc., need to be evaluated. Using regular security audits can further reduce risks to both data and infrastructure components.

When assessing the wider applicability of these systems, it is crucial to acknowledge certain limitations of the current studies. The majority of tests were carried out under standard road conditions and focused on a single type of smart crosswalk, which may not capture the full spectrum of variability encountered in urban settings. System performance could vary considerably in cities characterized by heavier traffic density, more intricate road configurations, or elevated crash rates. Therefore, extending future research to encompass a broader range of environmental and infrastructural contexts is essential for deriving more generalizable and robust conclusions.

3.3. System Compliance

While smart detection systems provide a robust technological base, it is becoming increasingly evident that their effectiveness depends on integration with complementary technologies and supportive policy interventions aimed at encouraging safer driver behavior. Real-time data analytics, IoT-enabled adaptive signaling, and predictive maintenance mechanisms are among the technologies that can enhance both the operational reliability and overall effectiveness of smart crosswalk infrastructure.

Overall, intersections represent critical points where numerous pedestrians must navigate road crosswalks despite inherent risks. Consequently, the implementation of a safe design, along with the strategic allocation of road space through signage, markings, and distinctive surface treatments can positively affect the behavior of pedestrians and cyclists at these locations, thereby helping to reduce the likelihood of crashes. Although crosswalks are generally perceived as safe crossing points, this assumption is not always accurate. While intersections offer some degree of protection—particularly benefiting vulnerable groups such as children and the elderly—a significant number of crashes still occur near these areas, especially within 50 m on either side of the smart crosswalk. To address these risks, various interventions have been introduced, including lowered curbs at intersections, which are especially vital for individuals with mobility impairments and tactile warning surfaces designed to aid those with visual disabilities. Additionally, features like refuge islands provide valuable support for pedestrians in safely crossing the roadway [40].

Some other aspects that have been developed to enhance road safety in crosswalk areas may include the following [18]:

• A system that continuously monitors the real-time positions and speeds of both pedestrians and vehicles, differentiating between pedestrian–vehicle conflict scenarios based on situational context. It can employ tailored warning mechanisms accordingly, including auditory prompts directed at pedestrians and dual alerts for both pedestrians and drivers via intelligent crosswalk signals utilizing flashing red and yellow lights. These measures effectively mitigate conflicts and reduce the risk of traffic crashes.
• A holistic framework that may integrate considerations of pedestrians’ psychological safety distances and incorporates modifications to vehicle behavior models based on an enhanced vehicle stopping sight distance approach. This integration not only enhances vehicle braking safety but also minimizes the psychological discomfort experienced by pedestrians during the braking process.

3.4. Maintenance and Lifecycle Costs

An important aspect of smart crosswalk deployment is the consideration of maintenance and lifecycle costs, which directly affect long-term sustainability and adoption. While the initial investment in infrastructure and technology can be substantial, the integration of predictive maintenance tools offers significant potential to reduce overall expenses. By leveraging IoT-enabled monitoring systems, potential faults in sensors, lighting, or communication units can be identified early, preventing costly failures and minimizing downtime.

Furthermore, the use of modular design approaches—where components such as LED studs, control cabinets, or motion sensors can be individually replaced without disrupting the entire system—substantially lowers repair costs and extends service life. Conducting a comprehensive lifecycle cost analysis is therefore essential, as it not only highlights the economic advantages of smart crosswalks over traditional infrastructure but also demonstrates their long-term cost-effectiveness in terms of reduced crash rates, lower maintenance needs, and enhanced operational reliability [25,41].

4. Evidence-Based Analysis of Incident Records at Crosswalk Areas

Considering the encouraging remarks on quantifiable improvement in the road safety of pedestrians in the literature, this section moves forward by providing evidence-based data from a Greek public database. In particular, the website of the Hellenic Statistical Authority [42] offers a unique opportunity for researchers to extract a variety of data related to incident records, including the type of roadway, the weather conditions, the status of the pavement surface, etc.

As per this study’s aim, the focus was put on urban areas to reveal trends of pedestrian safety over a long-term period. The analysis period included records for more than fifteen years, i.e., from 2005 up to 2022, thereby trying to highlight the potential long-term impact of advances in crosswalk designs on pedestrian safety. In particular, Figure 5 and Figure 6 present the yearly evolution of injury-based incidents and fatal accidents in urban Greek roads, where pedestrians were mainly involved through injuries and deaths, respectively.

It is important to notice that the total number of road incidents with injured pedestrians has progressively reduced during the analysis period. Notably, the descending trend for the period 2005–2014 was sharper than the trend in the following years. In this timeframe, both road design and infrastructure improvements have been implemented in many urban Greek areas. This aspect together with the advances in vehicle control systems can explain the progressive reduction in injury-based crashes. The lowest numbers were observed in 2020, probably due to the restrictions imposed by the COVID-19 pandemic, which drastically reduced the movement of both vehicles and pedestrians. Similar remarks have been observed in other similar studies, e.g., [43]. Despite the slight increase after 2020, the crash records appear even lower compared to the preceding years—an observation that could also be attributed to the shift towards lower speeds within urban areas, i.e., even less than 40 km/h [44].

As per the number of fatal accidents with involved pedestrians, some year-to-year discrepancies can be observed, but, overall, a descending trend is also observed herein. Noticeably the rate of fatal accidents to the total number of pedestrian-based incidents ranges from 5 to 9% over the whole analysis period.

A closer look in the crash datasets of [42] aimed to reveal the main cause for pedestrian involvement in the recorded crashes. Focusing on the timespan after 2014, where the total number of incidents was nearly stable, the noted reason according to the information on the conditions of the recorded crashes is given in Figure 7. Taking as a fact the road asset condition improvement within urban areas during the preceding years, it is of utmost importance to understand the main reasons that led to injuries or even death for pedestrians.

An analysis of pedestrian-related incidents between 2015 and 2022, based on a series of pie charts, reveals a consistent, yet concerning, trend: nearly 28–31% of the recorded incidents each year relate to cases where pedestrians cross the roads without using designated crosswalks (i.e., “gray” segments of the charts), and nearly 5–7% relate to cases where pedestrians do not perform any safety checks (i.e., “blue” segments of the charts). The relatively increased “gray” rate of 45% in 2020 is justified because of the COVID-19 restrictions in vehicle movements that made walking during road crossings less “strict”. Both segments of the charts underscore a persistent challenge in promoting safe pedestrian habits in urban environments.

However, a notable and encouraging improvement in infrastructure status is revealed in the reduction in the rate of the “green” segments over the same period. These segments represent cases where pedestrians were walking on a road without a crosswalk and failed to check for oncoming traffic. From 2015 to 2022, the percentage of these crashes steadily declined from 45% in 2015 up to 35% in 2022. In other words, this 10% reduction indicates a positive shift in either pedestrian awareness or surrounding road conditions. In particular, this improvement may be attributed to several factors.

• First, the gradual modernization of road networks across cities likely played a role, making pedestrian routes more visible and accessible.
• Second, the gradual choice for constructing and maintaining upgraded crosswalks, with better signage, road markings, and lighting, likely achieved a difference in pedestrian compliance.
• Another critical contributor could be the advancement of vehicle technology. The growing presence of new-generation vehicles equipped with automatic emergency braking (AEB) and pedestrian detection systems enhances overall safety of the road–vehicle ecosystem. These systems can compensate for human error, especially in scenarios where pedestrians cross roads unsafely or unexpectedly.

Finally, it is also worth mentioning that the increase in rates in the “red” segments is something that needs to be further investigated, as this might be a result of the variable level of experience of the persons who are responsible for crash recoding. Recent research, e.g., Ref. [5], agrees on the need to collect and report crash data through a standardized procedure, including as much and as accurate information as possible by experienced personnel, in order to perform efficient crash-cause classification and generate meaningful data for statistical reasons and for research fostering.

Overall, the data show that although risky pedestrian behavior persists, advances in the infrastructure status of road crosswalks together with technological advances can mitigate the consequences of pedestrian-related incidents. The downward trend in “gray” segments in Figure 7 is a positive sign, but it also acts as a critical reminder of the need to further invest in preventive smart infrastructure with a view of further decreasing the consequences of similar incidents.

5. Toward a Wider Applicability Framework

5.1. Discussion Points and Current Challenges

Building on the empirical evidence from Greek urban intersections (Section 4) and the technical insights into smart crosswalk design and operation (Section 2 and Section 3), this section discusses the challenges, strategic considerations, and future directions for broader adoption.

So far, the concept of a smart crosswalk has been consolidated as an essential component in the development of intelligent urban infrastructure, particularly in light of the growing presence of autonomous vehicles (AVs). As cities shift towards smarter and more interconnected environments, these crosswalks serve as critical interfaces between pedestrians and automated transport systems [45]. By integrating sensors, LED-based signaling, connectivity platforms, and real-time data analytics, smart crosswalks enhance both safety and traffic efficiency. Their ability to detect pedestrian or cyclist movement and to communicate this information to traffic control units and nearby vehicles, especially AVs, creates a dynamic system. Such a level of responsiveness is especially vital in dense urban areas where human unpredictability and vehicular automation must coexist and be proactively managed.

From the analysis presented in this paper, the significant reduction rate of 44% in pedestrian injuries and 52% in pedestrian fatalities between the initial year of the analysis (i.e., 2005) and the final year (i.e., 2022) confirms the catalytic effect of continuous improvements in crosswalk design and operation. However, the still considerable amount of pedestrian-related crashes highlights the need for consistent and coordinated investment in smart crosswalk technology, supported by a robust implementation framework and targeted strategic actions at both national and international scales. To this end, Figure 8 highlights the main challenges to achieving a high level of smart crosswalk effectiveness.

Despite their advantages, smart crosswalks require rigorous and ongoing maintenance to ensure long-term reliability. Sensors, lighting elements, and wireless communication components are subject to technical failure, weather-induced wear, and vandalism. Without systematic inspection and upkeep, these systems risk malfunctioning, potentially compromising public safety (recall Section 2.2.4). Urban authorities (municipalities, road operators, etc.) should therefore establish dedicated maintenance schedules and contingency plans as part of their broader smart city strategies.

In cases of maintenance process, appropriate maintenance plans and standards will alert road owners to apply the correct maintenance methods well ahead. To facilitate both the initial installation process, which includes the selection of materials and calibration of the systems, and the maintenance process, standardization is necessary. Undoubtedly, the existence of standards, guidelines, and protocols can ensure interoperability among technologies and provide confidence to road authorities for large-scale integration of smart crosswalks into broader smart-city frameworks.

Another crucial factor is user awareness and education [46]. Pedestrians must be trained to understand and properly respond to the visual or acoustic signals emitted by smart crosswalks. Public awareness campaigns, intuitive user interfaces, and integration into school safety programs are practical ways to ensure user engagement and safe behavior. On the same grounds, Pechteep et al. [47] confirm that education initiatives together with enforcement (e.g., parking restrictions), and public awareness campaigns are significant factors for crosswalk culture adaptation. Notably, enhanced road education can lead to reductions of up to 53% in injuries and 80% in fatalities according to a relevant study [48].

The technical effectiveness of smart crosswalks, as discussed in Section 2 and Section 3, provides a strong rationale for policy support and funding initiatives. Indeed, significant support has been observed on a worldwide scale regarding funding progress of the establishment of smart infrastructure systems, including the installation of smart crosswalks. For instance, in Greece, the Ministry of Digital Governance has launched several funding initiatives under the National Recovery and Resilience Plan to promote smart mobility projects, including smart crosswalks in cities such as Trikala, Thessaloniki, Ioannina, Attica Region, etc., [49,50].

At the European level, the Smart Mobility Strategy encourages the deployment of intelligent transport systems (ITSs) across member states, aligning with climate and safety goals [51]. These initiatives are suitable for a smart city environment and are all aligned with the Vision Zero strategy of the EU that aims to eliminate road deaths and severe injuries [52]. In the United States (U.S.), funding programs for smart crosswalks are available through U.S. Department of Transportation (USDOT) programs, such as the Strengthening Mobility and Revolutionizing Transportation (SMART) Grants Program for demonstrating smart community technologies and the Safe Streets and Roads for All (SS4A) Grant Program for implementing safety projects identified in comprehensive action plans. Other avenues include state-specific transportation alternatives programs (TAPs), and local or non-governmental grants from organizations like America Walks [53].

5.2. Future Prospects

While current findings highlight the promising role of smart crosswalks in enhancing safety, several research gaps remain to be addressed. One important direction involves the development of AI-driven predictive systems capable of anticipating pedestrian behavior and vehicle interactions in real time. By leveraging machine learning and computer vision, future systems could go beyond detection to forecast movement trajectories, thereby reducing false activations and improving the accuracy of early warnings. Moreover, such predictive tools could be particularly valuable in dense urban areas with high variability in pedestrian behavior.

Another avenue for future work concerns the integration of smart crosswalks with autonomous and connected vehicle fleets. As AVs become more prevalent, crosswalks will need to communicate directly with vehicles through Vehicle-to-Everything (V2X) protocols [54]. Further research is needed to evaluate how cooperative systems between infrastructure and AVs can optimize both safety and traffic efficiency in urban Greek intersections, building on the effectiveness of existing crosswalks so far, as implied from Section 4. Figure 9 illustrates future research directions in predictive systems and AV integration, building on the typical architecture of smart crosswalks (Section 2) and the analyzed data (Section 4).

Moving forward, comprehensive long-term cost–benefit analyses should be undertaken to assess not only the initial deployment costs but also the economic value of reduced crashes, lower maintenance expenses through predictive monitoring, and the societal benefits of safer urban environments. In other words, a life-cycle analysis of a smart crosswalk can ensure its long-term applicability and economic justification. However, the selection and deployment of smart crosswalks is not a one-size-fits-all solution. Crash-based prioritization might be needed. For instance, such systems may not be cost-effective at signalized, densely trafficked intersections, where conventional control mechanisms already provide sufficient safety performance. Nevertheless, the final decision might also assess the ad hoc pedestrian risk and cost-effectiveness. Another issue for maintenance procedures would be investigations into potential operation feedback systems, such that a timely diagnosis of faults can be ensured with limited or sample physical inspection; this could further maximize the cost-effectiveness of these new technologies and optimize the system’s lifecycle.

Upon studying these aspects, policymakers should be provided with additional evidence-based justification for large-scale adoption. In accordance with the Safe System Approach (SSA), smart crosswalks can ultimately serve as proactive safety components within a human-based framework, which encourages the use of transport systems that acknowledge human errors as inevitable. Therefore, the aim should be to proactively use an intelligent infrastructure design to minimize serious consequences and prevent injuries and/or fatalities.

6. Conclusions

The objective of this study was to assess the feasibility and potential of smart crosswalks as a means of enhancing road safety within the broader vision of smart city development. First, the research findings confirm that such systems may substantially reduce pedestrian–vehicle conflicts. Thereafter, statistical evidence from Greece, where pedestrians are involved in a considerable number of incidents, underscores the urgency of implementing these technologies. In this context, smart crosswalks can provide a concrete response to the pressing need for safer and smarter urban infrastructures. Key findings can be summarized as follows:

• Research evidence confirms the technical feasibility of smart crosswalks, highlighting key components, such as detection systems, LED signaling, and real-time monitoring, which enable smooth and efficient integration into intelligent urban infrastructure.
• The analysis of long-term Greek incident records involving pedestrians (analysis period: 2005–2022), showed a clear reduction in pedestrian injuries and fatalities at a rate of 44% and 52%, respectively. The percentage of incidents occurring in areas with no crosswalks decreased by nearly 10% during the last decade. This indicates that, among others, infrastructural interventions like improved crosswalk design can be translated into measurable benefits for pedestrian safety.
• Further deploying a framework for more targeted upgrades revealed challenges such as requirements and standards for modular construction and predictive maintenance, the need for user education through driver-awareness campaigns, and integration of funding in implementation action plans (e.g., pilot sections, initiatives toward smart mobility, etc.).