Pedestrians' Speed Analysis at Signalized Crosswalks

Pedestrian speed is essential for designing signal timings as well as for understanding pedestrian safety issues. This paper presents analysis of three types of pedestrian speeds (entry speed, crossing speed, and exit speed) at three signalized crosswalks in the State of Qatar. Pedestrian movements were tracked using TrafficAnalyzer software and data were analyzed to determine the effect of signal indications, crosswalk length, and crossing direction on pedestrian speeds. The results of this analysis showed that only 23.69% pedestrians crossed legally, during pedestrian green or pedestrian flashing green interval. Moreover, the pedestrian entry speeds were significantly affected by the pedestrian signal indications. Furthermore, the crossing speeds were positively correlated with crosswalk length for pedestrians crossing on green and red indications while pedestrian exit speeds were independent of crosswalk length but significantly affected by crossing direction. 2018 The Authors. Published by Elsevier B.V.Qatar National Research Fund, Qatar FoundationScopu

MODELLING THE SURROGATE SAFETY OF VARIOUS LEFT-TURN PHASE SEQUENCES

Left-turns are the most complex maneuvers in a signalized intersection. Based on the flow of the traffic volume through a given intersection, the left-turn phasing may be controlled in various fashions such as: protected only, permissive only, and protected/permissive. Following the introduction of the flashing yellow arrow (FYA) to the 2009 Edition of the Manual on Uniform Traffic Control Devices (MUTCD), many state agencies have implemented these indications for their left-turn permissive movements. Similar to the existing circular green (CG) permissive indication, the FYA requires drivers to yield to oncoming vehicles before making their left-turn. However, given the novelty of these traffic control devices there is a lack of standardization when it comes to the transition between protected and permissive left-turn phasing. A need exists to evaluate the surrogate safety of their implementation through a means of microsimulation evaluation. This research endeavor aims to model various protected-permissive left-turn (PPLT) phase sequences in the FHWA Surrogate Safety Assessment Model (SSAM). Both the FYA and circular green permissive left-turn indications will be implemented in VISSIM microsimulation models. Further, the phase sequencing for each permissive indication will comprise of two sequence options upon transitioning between protected and permissive left-turns; transitioning with and without the all-red clearance interval. Ultimately, this investigation will yield results to develop guidance for practitioners in designing the signal sequencing with PPLT phasing, particularly with the newly introduced FYA traffic control device

Modeling Driver-Pedestrian-Infrastructure Interactions at Signalized Midblock Crosswalks

Cities and metropolitan areas are increasingly facilitating pedestrians’ movement by the provision of pedestrian walking facilities. As pedestrian traffic increases, the risk of crash involvement increases, especially at midblock locations, where pedestrians are exposed to unsafe interactions with vehicular traffic. To improve pedestrians’ safety at midblock locations, various countermeasures are provided, which include signalized crosswalks. Several studies have analyzed driver-pedestrian interactions, as well as pedestrian-infrastructure interactions at signalized midblock crosswalks. However, more in-depth studies are necessary, due to shortfalls of study assumptions, which have led to the application of improper statistical models, as seen in the literature. Improved models are crucial, as they can be used to evaluate the factors affecting the effectiveness of countermeasures at signalized midblock crosswalks. Moreover, there are several aspects of pedestrian-infrastructure interactions that have not been studied in the previous research. This study, therefore, attempts to improve the methodologies for analyzing driver-pedestrian-infrastructure interactions at signalized midblock crosswalks. Specifically, this study is aimed towards: • Developing improved modeling methodology for the yielding compliance of drivers at signalized midblock crosswalks, which considers the time taken to yield right of way, and the transition states undergone during yielding. • Analyzing the risks associated with driver-pedestrian interactions at signalized midblock crosswalks. • Developing the framework for modeling the spatial and temporal crossing compliance of pedestrians at signalized midblock crosswalks. • Evaluating the influence of various crosswalk features, such as signs and markings, traffic-related variables, and pedestrian related factors on the safe utilization of signalized midblock crosswalks; these include factors influencing drivers’ yielding compliance, pedestrians’ crossing compliance, and pedestrians’ utilization of pushbuttons. The study data were collected from a total of twenty signalized midblock crosswalks located in the Las Vegas, Nevada metropolitan area. These crosswalks have varying geometric configurations, signalizations, traffic characteristics, and pedestrian flows. Five types of signalization; Circular Flashing Beacons (CFBs), Circular Rapid Flashing Beacons (CRFBs), Rectangular Rapid Flashing Beacons (RRFBs), Pedestrian Hybrid Beacons (PHBs), and Traffic Control Signals (TCSs) were studied in this research. The observational survey method was applied for data collection, whereby video cameras were used to collect driver-pedestrian interactions. The data extraction was performed by reviewing the videos and recording the information of interest in a spreadsheet, with a total of 2638 pedestrians crossing incidents recorded for analysis. A descriptive analysis was performed, and several statistical models were developed. Multistate hazard-based models are developed to model the yielding compliance of drivers. The transitional states while drivers are yielding right of way to pedestrians are defined as non-yield, “partial-yield” events (partial-yield, scenarios in which driver(s) in one lane yield, while other driver(s) in adjacent lane(s) in the same direction do not), and full-yield. Binary-based models are developed for modeling drivers’ spatial yielding compliance, pedestrians’ spatial crossing compliance, and pedestrians’ temporal crossing compliance. Rare Events Logistic Regression (RELR) is applied to evaluate the occurrence of partial-yield events and near-miss events. In addition to binary models, ordered models and multinomial models are developed and compared to model pedestrians’ spatiotemporal crossing compliance. The results of the multistate models reveal that signal type, number of vehicles within effective crosswalk distance, yield-here sign, and crossing zone factors have similar influence for transition from non-yield to full-yield, non-yield to partial yield, and partial yield to full yield. Thus, the results of the binary models for yielding compliance are only partially comparable to one transition of the multistate model (non-yield to full yield). Through the Rare Event Logistic Regression (RELR) model, this study finds that near crash events are highly associated with a single cross stage, a high number of lanes, and night time. In addition, this study reveals that there is a strong association between partial-yield and near-miss events. Additionally, it is found that for every second that traffic continues to flow while pedestrians are waiting to cross, the probability of a partial-yield event occurring increases by 2.1%, while that of near-crash events increase by about 3%. Moreover, the influence of the crosswalk features and the distance at which drivers yield with respect to the yield line (spatial yielding) was assessed. The logistic regression results for associating drivers’ spatial yielding results shows that the odds for drivers’ spatial yielding are high if the crosswalks are equipped with Rectangular Rapid Flashing Beacons (RRFBs) at the advanced pedestrians crossing signs (APCSs), in the presence of “State Law” and “PED XING” signs. On the other hand, long distances from stripes to the yield lines, multiple cross stages, and high Annual Average Daily Traffic (AADT) are associated with decreased spatial yielding compliance. Regarding pedestrian-infrastructure interactions, the logistic regression results reveal that the arrival sequence to a crosswalk has the highest impact on warning light activation tendencies. This means that the first arriving pedestrians are eight times more likely to press pushbuttons. Moreover, males, the elderly, children, and teens are less likely to press pushbuttons. Furthermore, pedestrians who are involved in secondary activities, such as carrying/holding objects in their hands, have a relatively low odds ratio of pressing the pushbutton, while phone use is a statistically insignificant factor. Several infrastructure and traffic factors, including flash-based signal types (CRFBs, CFBs and RRFBs), a high number of lanes, residential land use, and higher oncoming vehicle speeds are associated with an increase of pushbutton pressing. Among the models applied for spatiotemporal crossing compliance, the logistic regression outperformed the multinomial logit and the ordered logit models. The logistic regression results reveal that the active WALK signal and a crossing incident involving female(s) only are the factors positively associated with pedestrians’ spatiotemporal crossing compliance. On the other hand, wait time, children, and teens, as well as people who cross while using a phone or riding a bike are negatively associated with spatiotemporal crossing compliance. Based on the study’s findings, several recommendations are provided. The findings and recommendations from this study are expected to have academic, industry, and community benefits. Planners and engineers can benefit from this study by learning which countermeasures improve safety for both pedestrians and drivers. The models can be used by academicians and other practitioners to assess the scenarios in question. Improved pedestrian safety due to the selection of appropriate countermeasures, which fit a particular location, is a benefit that directly impacts the community

Analysis of Red-Light Violation Behavior of Pedestrian Two-Stage Crossing at a Signalized Intersection

Studying pedestrians’ twice-crossing behavior is of great significance to enhance safety and efficiency for pedestrians at signalized intersections. However, researchers have paid little attention to analyze and model pedestrians’ red-light running behavior on a two-stage crossing at signalized intersections. This paper focuses on analyzing the characteristics of pedestrian red-light violation behavior at the two stages, including the time distribution of violation behavior, the consistency of violation behavior, and the violation behavior in group.  A goal-oriented and time-driven red-light violation behavior model was proposed for pedestrian two-stage crossing. A video-recording method was used to collect field data, and the results show that pedestrians in the two directions present different red-light violation behaviors in time selection and violation count, as well as, pedestrians in the two stages of a direction present different red-light violation behaviors in time selection. The main reasons leading to the phenomena were analyzed, regarding from people’s cognitive psychology and visual perception. The results also show that the proposed model is effective in simulating pedestrian red-light violation behavior of twice crossing. This research provides a theoretical basis for optimizing signal timing, improving pedestrian safety and developing user-friendly transportation system

Pedestrian Behavior at Signalized Intersections Throughout Utah

Pedestrians and vehicles interact with each other all over the world. Pedestrian-vehicle interactions are most likely to occur at intersections. One way to streamline these interactions and reduce the number of potential conflicts is by using traffic signals. Signalized intersections were developed to increase the overall safety and efficiency of movements involving motorists and, later, pedestrians (Clark, 2022). The number of signalized intersections is increasing across the country as vehicle volumes increase. This means that pedestrian-vehicle conflicts are also increasing. Pedestrian-vehicle conflicts can have serious, even fatal, consequences if not appropriately managed. This study was a sponsored project by the Utah Department of Transportation (UDOT) to determine what factors are influencing pedestrian behavior and violations at intersections across the state. A pedestrian violation is defined in this study as a pedestrian crossing when and/or where there is opposing traffic with right-of-way and/or crossing in a location outside of a designated crosswalk. Both types of violations can create more opportunities for pedestrian-vehicle interactions. Pedestrian behavior was classified into crossing where pedestrians should not be and crossing when pedestrians should not be. These behaviors are dangerous and can create opportunities for pedestrian-vehicle conflicts. Different types of statistical analyses were done to determine factors which increase or decrease the number of pedestrian violations. Factors found to be significant across all types of violations included: total precipitation, 4-way intersections, pedestrian pushbuttons, crossing distance, and crossing time. An increase in theses variables predicted an increase in the rate of pedestrian violations. Factors noted in the literature, such as age, gender, and time of day, were also analyzed. Age and gender did not seem to have any significant influence on any violations except middle of the intersection crossings. Time of day factors, including peak hour and weekday vs. weekend, did not have any significant influence on pedestrian behavior

Evaluation of the effectiveness of countermeasures to enhance pedestrian safety

Pedestrian safety is a major concern in the United States because over 4,700 pedestrians are killed and 70,000 are injured annually. Nevada has one of the highest pedestrian fatality rates in the United States. Thus, there is a need to enhance pedestrian safety using existing and new strategies and to evaluate the effectiveness of these strategies. The objective of this research is to evaluate the effectiveness of various countermeasures to improve pedestrian safety. The countermeasures evaluated in this research include: (1) an in-pavement flashing light system, (2) pedestrian countdown signals, (3) turning traffic must yield to pedestrians signs, (4) a portable speed trailer, (5) in-roadway knockdown signs, (6) a high visibility crosswalk, (7) warning signs for motorists, (8) regulatory signs, and (9) advance yield markings; A before-and-after analysis was used to evaluate the selected strategies. Measures of effectiveness (MOEs) were used to evaluate the impacts of these countermeasures, including pedestrians\u27 and motorists\u27 behaviors. Data were collected immediately prior to the installation of each countermeasure and a few weeks after the installation of each countermeasure. Data were collected during both AM and PM peak periods. The data obtained from the two study periods (before installation and after installation) for each MOE were evaluated using statistical tools; Results from the analyses of the data show that the in-pavement flashing light system is an effective strategy to increase motorists\u27 yielding and to reduce average vehicle speeds at a location with low traffic and pedestrian volumes. The pedestrian countdown signal helps to improve pedestrians\u27 crossing behaviors. The observed mean vehicular speeds were higher when the pedestrian countdown timer was displayed on the pedestrian signal head than with the traditional pedestrian WALK phase. The installation of the sign turning traffic must yield to pedestrians increased motorists yielding behavior when they executed turning maneuvers on either red or green phases. The average vehicle speed was reduced upstream and downstream of the location of the portable speed trailer. The high visibility crosswalk, warning signs for motorists, regulatory signs for motorists, and advance yield markings at a mid-block location showed positive safety benefits in motorists\u27 and pedestrians\u27 behaviors; The MOEs used to evaluate countermeasures indicate improvements in both motorists\u27 and pedestrians\u27 behaviors. In most cases, these changed behaviors are positive and statistically significant. Even though these deployed strategies and their influence on pedestrians\u27 and drivers\u27 were effective in prevailing weather conditions and the geographic location of the Las Vegas metropolitan area, these findings are of value to other regions with similar traffic and pedestrian characteristics

Warrants for Right-Turn Flashing Yellow Arrow Signal Phases

The right-turn flashing yellow arrow (FYA) signal phasing is a new signal practice in the United States. The Manual on Uniform Traffic Control Devices MUTCD (2009) allocates a signal phasing section for the right-turn FYA, which requires a four-section head FYA signal. It supports multiple phases\u27 indications that guide the motorist through permissive, protected, and/or permissive/protected phases. For this dissertation, I investigated three permissive right-turn FYA signal phases in various traffic conditions and signal timing circumstances. The first permissive right-turn FYA signal phase is the tight-turn on impeding through (RTOIT) taking place during the cross-street through traffic movement. The second permissive right-turn FYA signal phase occurs during the opposing left-turn approach movement and so is called the right-turn on impeding left (RTOIL). The third permissive right-turn phase is a right-turn on through green impeded only by the side street pedestrians called the right-turn on adjacent through (RTOAT). I aimed to develop warrants leading to efficient implementation of permissive right-turn FYA signal phases based on microsimulation analysis. I developed multinomial logit models to establish a decision support system that predicts the efficiency attributes of the permissive right-turn FYA signal phases