Midblock Crosswalks Research Articles

Evaluation of Autonomous Driving Safety by Operational Design Domains (ODD) in Mixed Traffic

This study derived effective driving behavior indicators to assess the driving safety of autonomous vehicles (AV). A variety of operation design domains (ODD) in urban road networks, which include intersections, illegal parking, bus stop, bicycle lanes, and pedestrian crossings, were taken into consideration in traffic simulation analyses. Both longitudinal and interaction driving indicators were investigated to identify the driving performance of AVs in terms of traffic safety in mixed traffic stream based on simulation experiments. As a result of identifying the appropriate evaluation indicator, time-varying stochastic volatility (VF) headway time was selected as a representative evaluation indicator for left turn and straight through signalized intersections among ODDs related to intersection types. VF headway time is suitable for evaluating driving ability by measuring the variation in driving safety in terms of interaction with the leading vehicle. In addition to ODDs associated with intersection type, U-turns, additional lane segments, illegal parking, bus stops, and merging lane have common characteristics that increase the likelihood of interactions with neighboring vehicles. The VF headway time for these ODDs was derived as driving safety in terms of interaction between vehicles. The results of this study would be valuable in establishing a guideline for driving performance evaluation of AVs. The study found that unsignalized left turns, signalized right turns, and roundabouts had the highest risk scores of 0.554, 0.525, and 0.501, respectively, indicating these as the most vulnerable ODDs for AVs. Additionally, intersection and mid-block crosswalks, as well as bicycle lanes, showed high risk scores due to frequent interactions with pedestrians and cyclists. These areas are particularly risky because they involve unpredictable movements from non-vehicular road users, which require AVs to make rapid adjustments in speed and trajectory. These findings provide a foundation for improving AV algorithms to enhance safety and establishing objective criteria for AV policy-making.

Impact of Refuge Island in Two-Lane Roads on Pedestrian Crossing Behavior: A Virtual Reality Study

Crashes involving pedestrians are particularly common at unsignalized mid-block crosswalks, where, sometimes, vehicles do not yield to pedestrians. A refuge island (RI) is a countermeasure at mid-block crosswalks on two-lane roads to improve safety in pedestrian–vehicle conflicts. This study investigates the impact of RI at unsignalized mid-block crosswalks on pedestrian crossing behavior and conflict severity, considering vehicle approach speed and approach direction. A virtual reality experiment was designed to compare pedestrian crossing behaviors in different scenarios. Results revealed that at higher vehicle approaching speeds, pedestrians tended to accept shorter gaps, leading to a higher rate of unsafe crossings. Generally, in RI setting, pedestrians accepted significantly shorter gaps, which increases the operational efficiency of the crosswalk without significantly affecting the severity of conflicts with vehicles. Furthermore, the subjective evaluation of the pedestrians after the experiment clearly indicated their preference for the RI setting, as they reported a safer crossing experience.

Platoon control and external human–machine interfaces: innovations in pedestrian–autonomous vehicle interactions

At uncontrolled mid-block crosswalks, autonomous vehicles (AVs) are legally and safely obligated to yield to pedestrians, potentially exacerbating traffic congestion. This study explores integrating AV platoon control with eHMIs to examine its long-term potential for enhancing traffic flow safety and efficiency. A novel agent-based pedestrian-vehicle interaction framework is developed to evaluate the proposed strategy, accurately reproducing the heterogeneous behaviors of pedestrians and vehicles, such as pedestrians' risk tolerance, their responses to eHMIs, and vehicles' yielding mechanisms. Additionally, a platoon formation module is proposed to achieve the desired speed and inter-vehicular spacings from arbitrary initial condition. Simulation results indicate that implementing the proposed strategy reduced the conflict rate by 10%, increased the yielding rate by 11%, and decreased aggregate delay by 34.6% in typical flow conditions. The sensitivity analysis reveals that the effectiveness of the proposed strategy in improving traffic safety and efficiency increases with higher pedestrian and vehicle flow rates.

The impact of auditory advanced driver distraction warning devices on the behaviour of middle-aged drivers along urban roads

Driver distraction is one of the main causes of road crashes worldwide, with a relevant number of collisions, some fatal, especially among middle-aged drivers. In 2019, the European Regulation EU 2019/2144 mandated the installation of Advanced Driver Distraction Warning (ADDW) devices on all new vehicles by 2026. After the confirmation of its effectiveness in motorway driving, this driving simulation study evaluated the effectiveness of an auditory ADDW device in mitigating distraction on urban roads. Thirty middle-aged participants (fifteen females, aged between 25 and 35) were asked to read and respond to text messages on their cell phones, regardless of the device alert. They all drove (i) without being distracted (baseline condition), (ii) while distracted, and (iii) while distracted but supported by the ADDW device. Each participant faced three scenarios: (i) interaction with pedestrians at a mid-block crosswalk, (ii) driving in free-flow conditions on a dual-carriageway arterial, and (iii) driving behind another vehicle.The results revealed a degradation in driving performance and worsening safety conditions. In contrast to what was demonstrated for motorway driving, the ADDW device did not produce significant improvements in driving performance along urban roads. For drivers who continue to text while driving, no positive effect of the ADDW auditory device was observed. Unlike the motorway scenario, the urban environment produces a variety of stimuli that render distracted driving dangerous irrespective of the use of an ADDW.

Determinants of road user behavior at marked midblock crosswalks

Drivers do not properly respect pedestrian priority at marked mid-block crosswalks. This study assesses pedestrians and vehicles behavior at such locations. Video recording at two mid-block crosswalks was used to analyze twelve crossing attributes and their correlations. Analysis of 884 pedestrians’ and 2087 vehicle’s data showed that all demographic and crossing related attributes affected the crossing speed and crossing time of pedestrians. The average crossing speed of pedestrians was 1.3 m/s. Only parked car at crosswalk affected the waiting and delay times of pedestrians. Lastly, gender, and crossing related parameters were found to affect the accepted gap of pedestrians. The average accepted gap of pedestrians was 6.17seconds. Vehicle speeds before, at, and after crosswalks were statistically different and had mean values of 19.38kmph, 17.31kmph, and 20.40kmph respectively. Driver yielding rate was found to be 40% and was statistically significantly influenced by gender, dressing style, crossing in-group, and rolling behavior.

An extended intelligent driving model for autonomous and manually driven vehicles in a mixed traffic environment with consideration to roadside crossing

While the advantages of AVs and their impact on manually driven vehicles (MVs) have been widely discussed in continuous flow conditions, their performance under mixed traffic, intermitted flow conditions has yet to be properly studied. One of the representative scenarios is that vehicular flow is interrupted by roadside crossing obstacles such as pedestrians or cyclists. Since such interruption makes vehicles stop and go more frequently and creates random and complex traffic conflict, it has become a critical factor that can affect the driving performance of AVs. Therefore, this paper proposes a uniform traffic model (Pre_IDM+) to include roadside crossing impact in traffic flow analysis. The classical intelligent driving model (IDM) is extended into an obstacle-avoiding case, in which a novel pre-reaction workflow is introduced to describe yielding behavior and generate a reasonable braking trajectory. A real mixed traffic data near an un-signalized mid-block crosswalk is used to calibrate Pre_IDM+ and an accordingly microscope mixed traffic simulation platform is constructed. The simulation results show that discreet AVs can greatly avoid hard braking (−83.61%) and slightly improve passing speed (+5.11%) compared with MVs, while competitive AVs can maximize traffic efficiency (+7.03%) but will also deteriorate driving smoothness and comfort (−31.66%). Maintaining a sparse distribution of crossing sites along the road may contribute more to traffic stability and driving continuity compared with gathering all obstacles crossing at one location. This paper may help better understand the impact of AVs on general intermitted flow and give a reference to mixed traffic modeling towards a complex road condition.

Analysis of Factors Influencing Driver Yielding Behavior at Midblock Crosswalks on Urban Arterial Roads in Thailand

Globally, road traffic collisions cause over a million deaths annually, with pedestrians accounting for 23%. In developing countries, most pedestrian deaths occur on urban arterial roads, particularly at midblock crossings. This study analyzes the factors influencing driver yielding behavior at midblock crosswalks on urban arterial roads in Thailand. This study analyzed the factors influencing driver yielding behavior at the midblock crosswalk before and after the upgrade from a zebra crossing (C1) to a smart pedestrian crossing (C2), which is a smart traffic signal detecting and controlling pedestrians and vehicles entering the crosswalk. Video-based observations were used to assess driver yielding behavior, with multinomial logistic regression applied to develop driver yielding behavior models. The results revealed that the chances of a driver yielding at C2 were higher than at C1, and the yielding rate increased by 74%. The models indicate that the number and width of traffic lanes, width and length of crosswalks, vulnerable group, number of pedestrians, pedestrian crossing time, number of vehicles, vehicle speed, headway, post-encroachment time between a vehicle and pedestrian, and roadside parking are the significant factors influencing yielding behavior. These findings propose measures to set proper crosswalk improvements (e.g., curb extensions), speed reduction measures, enforcement (e.g., parking restrictions), public awareness campaigns, and education initiatives.

Effectiveness of smart LED strips at mid-block crosswalks under distracted driving conditions

We investigated the effectiveness of an LED-based smart mid-block crosswalk system in mitigating the detrimental effects of driver engagement in non-driving-related tasks (NDRTs) with behavioural, performance, and subjective measurements. We designed a 2 (Crosswalk: smart vs conventional) by 2 (Task complexity: low vs. high NDRT) within-subjects experiment. Thirty-six drivers drove along four urban scenarios in a static driving simulator. We collected data on driving behaviour (speed, reaction distance), and safety (minimum time-to-collision [MTTC]), as well as subjective driver ratings on the perceived task load and their trust in the technology used, and performance levels achieved while performing the NDRTs.Behavioural and performance observations showed that the smart mid-block crosswalk resulted in greater reaction distances and MTTC values when drivers interacted with pedestrians, thus indicating improved safety. Remarkably, the results also revealed that increased NDRT complexity does not negatively affect the smart crosswalk effectiveness in terms of driver-pedestrian collision prevention (i.e., MTTC does not decrease significantly). However, the NDRT complexity influenced driving performance in terms of speed and reaction distance at brake pedal pressure, with drivers exhibiting lower speeds and lower reaction distances with higher task loads. Moreover, the subjective ratings and performance levels while performing a NDRT reflected the experimental manipulation, with drivers perceiving higher task loads and performing worse in the higher NDRT complexity condition. Overall, the smart mid-block crosswalk led to a safer driver-pedestrian interaction compared to conventional crosswalks and achieved a good acceptance level both of which augur well for the widespread future installation of this technology.

Predicting Pedestrian Crossing Behavior at Unsignalized Mid-Block Crosswalks Using Maximum Entropy Deep Inverse Reinforcement Learning

Predicting Pedestrian Crossing Behavior at Unsignalized Mid-Block Crosswalks Using Maximum Entropy Deep Inverse Reinforcement Learning

Vehicle Delay Model for Signalized Midblock Crosswalk Under Mixed Traffic Conditions

For signalized locations, delay is one of the key parameters in assessing the level of service and redesigning the traffic signals. Around the world, Highway Capacity Manual (HCM) and Webster delay models are commonly used in calculating the vehicle delay at signalized intersections, notwithstanding that these models assume homogeneous traffic conditions and lane discipline. Furthermore, it is worth noting that previous studies have mostly focused on developing delay models for signalized intersections, whereas signalized midblock crosswalks were overlooked by past researchers. In view of this, the current study presents a modified vehicle delay model for signalized midblock crosswalks (SMCs) under mixed traffic conditions. Mixed traffic conditions refers to diverse vehicles, complex interactions, and no lane discipline on the road—conditions which are usually noticed in developing nations. The HCM vehicle delay model is modified in the current study by incorporating factors related to mixed traffic conditions and SMCs. To test the accuracy of the proposed model, it was validated with the field delay using data collected at other SMCs in Hyderabad, India. Field delay was calculated by plotting the measured queue length against the signal cycle length. The performance metrics of root mean square error (RMSE), mean absolute percentage error, Nash–Sutcliffe efficiency, RMSE-observations standard deviation ratio, and percent bias were used to test the accuracy of the proposed model. Results revealed that the proposed model yielded the lowest error rates and the highest correlation coefficients between modeled and actual vehicle delay. The maximum error between the field delay and the modeled delay was found to be less than 5%.

USER PERCEPTIONS BASED LEVEL OF SERVICE FOR UNCONTROLLED MID-BLOCK CROSSINGS USING TRAFFIC SURVEYS AND ITS REGRESSION ANALYSIS

The exponential growth of urban populations has led to a substantial increase in traffic on urban roads, prompting extensive research into optimizing road networks for vehicular traffic. However, there has been a noticeable lack of attention given to the safety and well-being of pedestrians. One particularly perilous scenario for pedestrians occurs at mid-block crossing locations where well-designed crosswalks are absent. In such areas, pedestrians are forced to identify safe crossing points, often with limited safety measures in place. Ensuring the safety, convenience, comfort, and minimal delay for pedestrians in these situations is imperative. To address this gap, a comprehensive evaluation of the quality of service at mid-block crosswalks is necessary. This research study focused on assessing the quality of service at non-signalized mid-block pedestrian crossings from the perspective of consumers. The analysis employed regression techniques and gathered data from four distinct mid-block crossing locations in different areas of Visakhapatnam. Data collection involved video image surveillance to obtain data on pedestrian quantities, volume-based characteristics, walking speeds, capacity, and gap sizes, complemented by questionnaires to capture real-time experiences and opinions of pedestrians. The questionnaire encompassed various variables affecting crossing quality, including demographic information and pedestrian perceptions of safety and comfort. Pedestrians rated these attributes on a scale of one to six, with their scores serving as variables for subsequent analysis. This approach seeks to ensure that pedestrians have the safest, most comfortable, and efficient means to cross the street while minimizing potential delays. Keywords:Pedestrian safety,Mid-block crossing,Quality of service,Urban road traffic,Crosswalk design, Consumer perspective,Data collection, ,Questionnaires,Perception,Safety measures,Comfort, Demographic information,,Efficiency,Delay mitigation,Regression analysis,Vehicular traffic optimization,Urbanization impact.

Pedestrian Waiting Delay at Signalized Midblock Crosswalks under Mixed Traffic Conditions

Pedestrian Waiting Delay at Signalized Midblock Crosswalks under Mixed Traffic Conditions

Pedestrian–vehicle interactions at unsignalized mid-block crosswalks: Effects on traffic flow, CO[formula omitted] emissions, and energy dissipation

Unsignalized mid-block crosswalks are adopted to regulate unauthorized crossings by promoting drivers’ yielding to pedestrians. Although pedestrian–vehicle interactions at crosswalks have been widely studied, the effects of such facilities regarding traffic flow and emissions have been overlooked. This paper presents a vehicle–pedestrian cellular automata model to analyze the effects of two types of crosswalk systems: raised and zebra, on traffic characteristics. The model allows microscopically studying the impact of the induced speed heterogeneity in terms of traffic flow, CO2 emissions, and kinetic energy dissipation. Simulation results show that traffic flow experiences four phases in both systems: maximum current, congestion, jamming, and blocking; with second-order transitions among them. The maximum current phase is the only one with free-flow conditions shrinking faster in the system with a raised crosswalk than in the one with zebra. Both systems reach the blocking phase when the pedestrian entrance rate surpasses a critical value. However, raised crosswalk has lesser repercussions in CO2 emission and energy dissipation by eliciting traffic calm. This study enhances the comprehension of the impacts of mid-block crosswalks, depending on the manner in which they are deployed.

Interaction-Aware Decision-Making for Autonomous Vehicles

Complex, dynamic, and interactive environment brings huge challenges to autonomous driving technologies. Because of the strong interactions between different traffic participants, autonomous vehicles (AVs) must learn how to interact with other road users. Failure to consider interaction when making decisions may result in safety issues. In this paper, an interaction-aware decision-making approach is proposed for AVs. First, focusing on the interaction at uncontrolled mid-block crosswalks, the game theory is used to model the vehicle-pedestrian interaction (VPI). Then, an interaction inference framework is developed using the interaction model to obtain interaction information with pedestrians. Besides, a collaborative action planning method is proposed to generate collaborative actions. More importantly, interactive decision-making is formulated as an optimization problem by considering the task item and action item. Furthermore, considering pedestrians’ different levels of cooperation, the social force pedestrian model is developed. And then, a highly interactive environment is constructed. Finally, qualitative and quantitative evaluations are carried out against three baseline methods. The result shows that our method can interact with different pedestrians and balance safety and efficiency compared to baseline methods.

Pedestrian delay models for compliant & non-compliant behaviour at signalized midblock crosswalks under mixed traffic conditions

The present study aimed to propose new pedestrian delay models for Signalized Midblock Crosswalks (SMC) for mixed traffic conditions. A detailed study of the literature revealed that most of the existing pedestrian delay models were developed for signalized intersections. Thus, the need for the study was established and data were collected at eight SMC in Hyderabad, one of the most densely populated metropolitan cities in India, using video-graphic technique. Two delay models were developed based on the compliance behaviour and non-compliance behaviour of pedestrians. Both models have two components i.e., waiting delay and crossing delay where the latter has two subset components i.e., frictional delay and pedestrian-vehicle interaction delay. The bidirectional effect (pedestrian-pedestrian interaction while crossing the road) of pedestrians was addressed as frictional delay while the non-compliance behaviour by pedestrians and vehicles was addressed as pedestrian-vehicle interaction delay in the present models. The waiting delay component was defined by modifying the Webster delay model for non-uniform pedestrian arrivals. The proposed delay models yielded an error of 5% and 7% for compliance behaviour model and non-compliance behaviour model respectively. The proposed models can be used for optimizing the signal timings and defining Level of Service (LOS) of facilities.

Lighting Strategies to Increase Nighttime Pedestrian Visibility at Midblock Crosswalks

In the last decade, pedestrian fatalities at night, especially at midblock locations, have been increasing at an alarming rate. Lighting is an effective countermeasure in reducing nighttime crashes. However, few studies have evaluated the effects of crosswalk lighting on pedestrian visibility at midblock locations. There is an existing need to develop lighting designs that increase pedestrian visibility. Further, the safety effects of lighting have never been directly compared to other pedestrian-crossing treatments (such as flashing signs, rectangular rapid flashing beacons (RRFBs), etc.). Thus, in order to make effective recommendations for increasing nighttime pedestrian visibility, it is important to compare the visibility benefits of crosswalk lighting designs with and without pedestrian-crossing treatments. This study evaluated the visual performance of five midblock crosswalk lighting designs along with two pedestrian safety countermeasures at three light levels on a realistic midblock crosswalk. Visual performance was measured by calculating the distance at which the participants could detect a child-sized mannequin under the evaluated conditions. The results showed that midblock crosswalks should be illuminated to an average vertical illuminance of 10 lux to ensure optimal pedestrian visibility. Lighting designs that render the pedestrian in positive contrast (area in front of the crosswalk is illuminated) are recommended to increase pedestrian visibility. It is also recommended that pedestrian-crossing treatments, such as RRFBs and flashing signs, should be used with lighting to increase nighttime visibility.

Red LED Strip Signalling Pedestrian Presence at Uncontrolled Mid-block Crosswalks

A relevant number of collisions between vehicles and pedestrians occur at night because of the reduced capacity of a driver to perceive and react to the presence of pedestrians at crosswalks. To reduce this risk of collision, new smart road technologies have been introduced. This study aims to evaluate the effectiveness of a red LED strip that warns the driver of the presence of pedestrians at unsignalized mid-block crosswalks at night-time. The technology consists of LED strips installed near the crosswalk on the side of oncoming vehicles. The LED is activated when a sensor detects a pedestrian approaching the crosswalk. In this driving simulation experiment, three different urban mid-block crosswalks were evaluated: (i) without an LED strip (baseline), (ii) with a fixed LED strip, and (iii) with a flashing LED strip. Each scenario was tested for three different levels of pedestrian time gap acceptance (PTGA) (i.e., 4, 6, 8 s) and two road sections (i.e., 1 lane vs. 2 lanes). Thirty-six participants took part in a within-subjects’ design. During the experiment, the minimum time to collision (mTTC), the post-encroachment time (PET), maximum vehicle speed, and reaction distance were monitored to quantitatively compare the different levels of vehicle-pedestrian interaction. Compared to the baseline, the LED strip resulted in a safer driver-pedestrian interaction, with an average increase in mTTC of 1.13 s, PET of 0.66 s, and a longer average reaction distance of 7.9 m. However, a slight (albeit not statistically significant) increase in speed was observed following installation of the LED strip. Furthermore, no significant differences were observed between fixed and flashing LED strips. Overall, these results confirm the LED strips effectiveness in alerting the driver to the presence of a pedestrian, thus increasing the safety of their interaction. Further studies should confirm these findings in a more ecological way, e.g., evaluating the safety impact of this technology under different weather and distracted driving conditions.

Comparison of Pedestrian Delay Models at Signalized Midblock Crossings Under Mixed Traffic Conditions

In the field of transportation engineering, one of the most important factors for the traffic engineers and road users (pedestrian and vehicle) is the delay which governs the LOS of a facility. Past studies shows that various delay models like HCM, Webster, and Austroads work well for the homogeneous traffic conditions. However, Limited studies were done on mixed traffic conditions like in India and in other developing countries. Apart from that, all the models were developed based on the conditions of signalized intersection whereas signalized midblock crosswalks were completely overlooked by the researchers. The present study aims to compare pedestrian field delay at signalized midblock sections with the existing models. Six mid-block crossings have been selected from Hyderabad, India and data was collected using video-graphic technique. Field Pedestrian waiting delays were measured by plotting queue length against cycle time and area under the curve was calculated using Simpson's 1/3rd rule. Field crossing delay was calculated as the difference between actual crossing time and ideal crossing time. The performance of all the models were evaluated using t-test and other performance indices like MAPE, RMSE and R2. It was observed from the statistical tests that there is a significant difference between the means of field delay and delay by existing models. Also all the existing models yielded an error of more than 20% with an R2 value of less than 0.3. Calibrated results can be used in the modelling of new pedestrian delay for signalized midblock crosswalks.

The implications of situation and route familiarity for driver-pedestrian interaction at uncontrolled mid-block crosswalks

Most routine daily trips take place along the same route, a fact that previous studies have not investigated together with the repeated situation of conflicting with other road users. Consequently, our study addresses driver behaviour by separating the driving experience into three categories: (i) drivers unfamiliar with the route, (ii) those route-familiar, and (iii) situation-familiar drivers. The specific case of driver-pedestrian interaction at uncontrolled mid-block crosswalks is investigated. A multi-level factorial experiment including (i) crosswalk design (linear sidewalk and curb extension), (ii) driver familiarity, and (iii) pedestrian time gap acceptance (4, 6, and 8 s) was conducted using a driving simulator. Fifty-two participants were divided into four groups and stratified by age, gender, and driving experience. The minimum instantaneous time to collision, post-encroachment time, maximum car deceleration, and maximum car speed were all used as surrogate safety measures (SSM).Route-familiarity led to higher speed, while situation-familiarity positively affected driving behaviour making drivers more inclined to decrease their speed at circa 100 m before a crosswalk. The curb extension layout enhanced pedestrian safety and mitigated any adverse effects due to familiarity, with a particularly relevant impact on SSM at low accepted time gaps for pedestrians. Situation- and route-familiarity treatment protocols lead to different behaviours among drivers, indicating a clear need to account for these two familiarity levels in experiments on safety-related countermeasures.

Evaluating the Pedestrian Gap Acceptance in Semicontrolled Midblock Crosswalks with an Integrated AHP-FL Approach

Evaluating the Pedestrian Gap Acceptance in Semicontrolled Midblock Crosswalks with an Integrated AHP-FL Approach