The Experts below are selected from a list of 7608 Experts worldwide ranked by ideXlab platform
Hideki Nakamura - One of the best experts on this subject based on the ideXlab platform.
-
effects of bi directional pedestrian flow characteristics upon the capacity of signalized Crosswalks
Procedia - Social and Behavioral Sciences, 2011Co-Authors: Wael K.m. Alhajyaseen, Hideki Nakamura, Miho AsanoAbstract:Existing manuals do not provide clear specifications regarding the required crosswalk width under various pedestrian demand combinations and properties. Furthermore, they don’t offer any quantification regarding the effects of bi-directional flow and pedestrian flow composition upon capacity. This paper analyzes the effects of pedestrian age group and the interaction between bi-directional pedestrian flows on the capacity of signalized Crosswalks. Three pedestrian age groups are defined: middle-age, pupils and elderly. A previous developed methodology for modeling pedestrian flows at signalized Crosswalks is utilized to generate the fundamental diagrams of pedestrian flow. It is found that the maximum reduction in capacity occurs at roughly equal pedestrian flows from both sides of the crosswalk. Further, it is concluded that elderly pedestrians might cause a significant reduction in capacity up to 30%.
-
Quality of pedestrian flow and crosswalk width at signalized intersections
Iatss Research, 2010Co-Authors: Wael K.m. Alhajyaseen, Hideki NakamuraAbstract:Among various pedestrian facilities, signalized Crosswalks are the most complex and critical ones. Their geometry and configuration including width, position and angle directly affect the safety, cycle length and resulting delays for all users. Existing manuals do not provide clear and rational specifications for the required crosswalk width under different pedestrian demand combinations and properties. Furthermore, they do not consider the bi-directional flow effects on crossing speed and time when addressing pedestrian flow at signalized Crosswalks. However, quantifying the effects of such interactions on the behavior of pedestrian flow is a prerequisite for improving the geometric design and configuration of signalized Crosswalks. The objective of this paper is to develop a methodology for estimating the required crosswalk width at different pedestrian demand combinations and a pre-defined LOS. The developed methodology is based on theoretical modeling for total pedestrian platoon crossing time, which consists of discharge and crossing times. The developed models are utilized to generate the fundamental diagrams of pedestrian flow at signalized Crosswalks. A comprehensive discussion about the effects of bi-directional flow and various pedestrian age groups on the characteristics of pedestrian flow and the capacity of signalized Crosswalks is presented. It is found that the maximum reduction in the capacity of signalized Crosswalks occurs at roughly equal pedestrian flows from both sides of the crosswalk. By utilizing existing LOS thresholds for pedestrian flow at signalized Crosswalks, the required crosswalk widths for various pedestrian demand combinations are proposed for implementation.
-
Design Criteria for Crosswalk Width and Position at Signalized Intersections
International symposium on Highway Geometric Design, 2010Co-Authors: Wael K.m. Alhajyaseen, Hideki NakamuraAbstract:Existing optimization methodologies for intersection operations assumes a fixed geometric design; however to produce the best performance, the geometry and operational system should be optimized simultaneously. Crosswalks at signalized intersections are complex and critical pedestrian facilities. Their geometry and configuration directly affect the safety, cycle length and resulting delays for all users. As Crosswalks become wider or they are placed further upstream, the cycle length will increase due to the all-red time requirement, which deteriorates the overall mobility levels of signalized intersections. In contrast, when crosswalk width decreases, the required minimum pedestrian crossing time increases due to the bi-directional pedestrian flow effects, which leads to longer cycle length. Furthermore, existing manuals and guidelines do not offer any specification for the required crosswalk width under various pedestrian demand conditions. This study aims to develop new criteria for designing crosswalk width at signalized intersections, which can optimize the performance of signalized intersections from the viewpoint of vehicular traffic and pedestrians. The proposed methodology considers pedestrian demand and its characteristics, vehicle demand and the geometric characteristics of the intersection. The concept of optimized crosswalk width is proposed and demonstrated through a case study. Moreover, a comprehensive discussion regarding the existing strategies on positioning Crosswalks is presented. The merits and drawbacks of each pattern are discussed. A previously developed methodology for modeling pedestrian flow at signalized Crosswalks is utilized to estimate crossing time requirements and the reduction in crossing speed due to the bi-directional flow effects. It was found that at signalized intersections, which are characterized by low pedestrian and high vehicle demands, crosswalk width of 2 meters is appropriate to minimize cycle length and resulting delays for all users including pedestrians.
-
Methodology for Modeling Pedestrian Platoon Discharge and Crossing Times at Signalized Crosswalks
Transportation Research Board, 2009Co-Authors: Wael K.m. Alhajyaseen, Hideki NakamuraAbstract:Optimizing crosswalk configurations including width, position and angle is an important concern to improve the overall performance of signalized intersections. Quantifying the effects of bi-directional flow and crosswalk width on pedestrian walking speed and crossing time is a prerequisite for improving the geometric design and configuration of signalized Crosswalks. The time used by a pedestrian platoon to cross a signalized crosswalk is divided into discharge time and crossing time. Discharge time is a function of pedestrian demand and crosswalk width while pedestrian crossing time is basically a function of crosswalk length and walking speed. However when pedestrian demand increases at both sides of the crosswalk, crossing time increases due to interactions between conflicting pedestrian flows. A variety of methods have been developed for determining appropriate pedestrian crossing times. Although many of these methods have useful applications, most of them have shortcomings when considering the effects of bi-directional flow on crossing time. No consideration is given to deceleration or reduction in walking speed that results from the interaction between conflicting flows. Furthermore existing models tend to underestimate the discharge time necessary for a pedestrian platoon waiting at the edge of the crosswalk. This study proposes a new methodology for modeling pedestrian discharge and crossing times. Discharge time is modeled by using shockwave theory while crossing time is modeled by applying aerodynamic drag theory. The developed methodology provides a rational quantification for the effects of bi-directional pedestrian flow and crosswalk geometry on walking speed and crossing time.
Wael K.m. Alhajyaseen - One of the best experts on this subject based on the ideXlab platform.
-
ANT/SEIT - Pedestrians’ Speed Analysis at Signalized Crosswalks
Procedia Computer Science, 2018Co-Authors: Deepti Muley, Wael K.m. Alhajyaseen, Mohamed Kharbeche, Mohammed Al-salemAbstract:Abstract 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.
-
analysis of pedestrian clearance time at signalized Crosswalks in japan
Procedia Computer Science, 2014Co-Authors: Miho Iryoasano, Wael K.m. AlhajyaseenAbstract:At signalized Crosswalks, pedestrian clearance time is a key design parameter for ensuring safe pedestrian crossing. It is generally defined as the time required by pedestrians who enter Crosswalks at the end of the green indication to complete crossing before conflicting vehicular traffic movements are released. In Japan, pedestrian green indications are followed by pedestrian flashing green (PFG) indications during which time pedestrians are not allowed to start crossing and those in the crosswalk have to finish crossing to either side of the crosswalk; as such, some pedestrians are expected to return to the side they came from. Therefore, PFG intervals are designed to be shorter than the necessary clearance time. Instead, relatively longer red buffer intervals (BI) are provided between the end of the PFG and the succeeding vehicle green indication. This study clarifies the differences between signal setting concepts in various countries and analyses pedestrian clearing behaviors under the Japanese signal control system. Empirical analyses show that the current PFG and BI settings in Japan are shorter than the necessary clearance time and the settings in the US and Germany. As a result, most observed pedestrians who started crossing after the onset of PFG cannot finish crossing before its end and cannot even finish before the succeeding vehicle green indication.
-
effects of bi directional pedestrian flow characteristics upon the capacity of signalized Crosswalks
Procedia - Social and Behavioral Sciences, 2011Co-Authors: Wael K.m. Alhajyaseen, Hideki Nakamura, Miho AsanoAbstract:Existing manuals do not provide clear specifications regarding the required crosswalk width under various pedestrian demand combinations and properties. Furthermore, they don’t offer any quantification regarding the effects of bi-directional flow and pedestrian flow composition upon capacity. This paper analyzes the effects of pedestrian age group and the interaction between bi-directional pedestrian flows on the capacity of signalized Crosswalks. Three pedestrian age groups are defined: middle-age, pupils and elderly. A previous developed methodology for modeling pedestrian flows at signalized Crosswalks is utilized to generate the fundamental diagrams of pedestrian flow. It is found that the maximum reduction in capacity occurs at roughly equal pedestrian flows from both sides of the crosswalk. Further, it is concluded that elderly pedestrians might cause a significant reduction in capacity up to 30%.
-
Quality of pedestrian flow and crosswalk width at signalized intersections
Iatss Research, 2010Co-Authors: Wael K.m. Alhajyaseen, Hideki NakamuraAbstract:Among various pedestrian facilities, signalized Crosswalks are the most complex and critical ones. Their geometry and configuration including width, position and angle directly affect the safety, cycle length and resulting delays for all users. Existing manuals do not provide clear and rational specifications for the required crosswalk width under different pedestrian demand combinations and properties. Furthermore, they do not consider the bi-directional flow effects on crossing speed and time when addressing pedestrian flow at signalized Crosswalks. However, quantifying the effects of such interactions on the behavior of pedestrian flow is a prerequisite for improving the geometric design and configuration of signalized Crosswalks. The objective of this paper is to develop a methodology for estimating the required crosswalk width at different pedestrian demand combinations and a pre-defined LOS. The developed methodology is based on theoretical modeling for total pedestrian platoon crossing time, which consists of discharge and crossing times. The developed models are utilized to generate the fundamental diagrams of pedestrian flow at signalized Crosswalks. A comprehensive discussion about the effects of bi-directional flow and various pedestrian age groups on the characteristics of pedestrian flow and the capacity of signalized Crosswalks is presented. It is found that the maximum reduction in the capacity of signalized Crosswalks occurs at roughly equal pedestrian flows from both sides of the crosswalk. By utilizing existing LOS thresholds for pedestrian flow at signalized Crosswalks, the required crosswalk widths for various pedestrian demand combinations are proposed for implementation.
-
Design Criteria for Crosswalk Width and Position at Signalized Intersections
International symposium on Highway Geometric Design, 2010Co-Authors: Wael K.m. Alhajyaseen, Hideki NakamuraAbstract:Existing optimization methodologies for intersection operations assumes a fixed geometric design; however to produce the best performance, the geometry and operational system should be optimized simultaneously. Crosswalks at signalized intersections are complex and critical pedestrian facilities. Their geometry and configuration directly affect the safety, cycle length and resulting delays for all users. As Crosswalks become wider or they are placed further upstream, the cycle length will increase due to the all-red time requirement, which deteriorates the overall mobility levels of signalized intersections. In contrast, when crosswalk width decreases, the required minimum pedestrian crossing time increases due to the bi-directional pedestrian flow effects, which leads to longer cycle length. Furthermore, existing manuals and guidelines do not offer any specification for the required crosswalk width under various pedestrian demand conditions. This study aims to develop new criteria for designing crosswalk width at signalized intersections, which can optimize the performance of signalized intersections from the viewpoint of vehicular traffic and pedestrians. The proposed methodology considers pedestrian demand and its characteristics, vehicle demand and the geometric characteristics of the intersection. The concept of optimized crosswalk width is proposed and demonstrated through a case study. Moreover, a comprehensive discussion regarding the existing strategies on positioning Crosswalks is presented. The merits and drawbacks of each pattern are discussed. A previously developed methodology for modeling pedestrian flow at signalized Crosswalks is utilized to estimate crossing time requirements and the reduction in crossing speed due to the bi-directional flow effects. It was found that at signalized intersections, which are characterized by low pedestrian and high vehicle demands, crosswalk width of 2 meters is appropriate to minimize cycle length and resulting delays for all users including pedestrians.
Thiago Oliveira-santos - One of the best experts on this subject based on the ideXlab platform.
-
Handling Pedestrians in Crosswalks Using Deep Neural Networks in the IARA Autonomous Car
2018 International Joint Conference on Neural Networks (IJCNN), 2018Co-Authors: Rânik Guidolini, Claudine Badue, Lucas G. Scart, Luan F. R. Jesus, Vinicius B. Cardoso, Thiago Oliveira-santosAbstract:In this work, we propose a subsystem to handle pedestrians in Crosswalks using deep neural networks for the IARA autonomous car, which relies on camera and LIDAR data fusion. Crosswalks' positions were manually annotated in IARA's map. Pedestrians are detected in the camera image using a convolutional neural network (CNN). Then, pedestrians' positions in the map are obtained by fusing their positions in the image with the LIDAR point cloud. Subsequently, if a pedestrian position is inside the crosswalk area, the crosswalk is set as busy. Finally, a busy crosswalk message is published to the High-Level Decision Maker subsystem. This subsystem selects the car's behavior according to the crosswalk condition and propagates this decision down through the control pipeline, in order to make the car drive correctly through the crosswalk area. The Pedestrian Handler subsystem was evaluated on IARA, which was driven autonomously for various laps along a real and complex circuit with various Crosswalks. In all passages through Crosswalks, the Pedestrian Handler dealt with pedestrians as expected, i.e., without any human intervention.
-
IJCNN - Handling Pedestrians in Crosswalks Using Deep Neural Networks in the IARA Autonomous Car
2018 International Joint Conference on Neural Networks (IJCNN), 2018Co-Authors: Rânik Guidolini, Claudine Badue, Lucas G. Scart, Luan F. R. Jesus, Vinicius B. Cardoso, Thiago Oliveira-santosAbstract:In this work, we propose a subsystem to handle pedestrians in Crosswalks using deep neural networks for the IARA autonomous car, which relies on camera and LIDAR data fusion. Crosswalks’ positions were manually annotated in IARA’s map. Pedestrians are detected in the camera image using a convolutional neural network (CNN). Then, pedestrians’ positions in the map are obtained by fusing their positions in the image with the LIDAR point cloud. Subsequently, if a pedestrian position is inside the crosswalk area, the crosswalk is set as busy. Finally, a busy crosswalk message is published to the High-Level Decision Maker subsystem. This subsystem selects the car’s behavior according to the crosswalk condition and propagates this decision down through the control pipeline, in order to make the car drive correctly through the crosswalk area. The Pedestrian Handler subsystem was evaluated on IARA, which was driven autonomously for various laps along a real and complex circuit with various Crosswalks. In all passages through Crosswalks, the Pedestrian Handler dealt with pedestrians as expected, i.e., without any human intervention.
Charles V Zegeer - One of the best experts on this subject based on the ideXlab platform.
-
the marked crosswalk dilemma uncovering some missing links in a 35 year debate
Transportation Research Record, 2008Co-Authors: Meghan Fehlig Mitman, David R. Ragland, Charles V ZegeerAbstract:Largely in response to several landmark safety studies, as an official or unofficial policy, many agencies across the U.S. have elected to remove marked Crosswalks at uncontrolled intersections, or have shown resistance to installing them in the first place. This approach results in unacceptable pedestrian mobility restrictions, yet such restrictions are often not considered in policy-making. As such, there is a need for roadway system owners to develop strategic safety guidelines to address the marked crosswalk dilemma. Since 2005, the UC Berkeley Traffic Safety Center, in a study funded by the California Department of Transportation (Caltrans), has focused on developing a better understanding of driver and pedestrian behavior and safety in both marked and unmarked Crosswalks in an effort to recommend more informed crosswalk policies. The study was designed to fill key gaps in the literature by analyzing pedestrian and driver behavior and knowledge of right-of-way laws regarding marked and unmarked Crosswalks. The study also focused on driver and pedestrian behavior with regard to multiple threat scenarios, the most common type of pedestrian collisions at uncontrolled intersections. This paper summarizes results from field observations of driver and pedestrian behavior at marked and unmarked Crosswalks on low speed, two-lane and multi-lane roads. The behavioral observations are interpreted in light of findings reported by Mitman and Ragland (2007) from surveys and focus groups regarding driver and pedestrian knowledge of right-of-way laws. The paper concludes with recommendations for a comprehensive crosswalk safety policy to strategically address crash risk at uncontrolled Crosswalks.
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations final report and recommended guidelines
2005Co-Authors: Charles V Zegeer, H H Huang, Peter Lagerwey, Richard J Stewart, John Feaganes, B J CampbellAbstract:Pedestrians are legitimate users of the transportation system, and they should, therefore, be able to use this system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. The purpose of this study was to determine whether marked Crosswalks at uncontrolled locations are safer than unmarked Crosswalks under various traffic and roadway conditions. Another objective was to provide recommendations on how to provide safer crossings for pedestrians. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 unmarked comparison sites. All sites in this study had no traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, median type, speed limit, and other site variables. Poisson and negative binomial regressive models were used. The study results revealed that on two-lane roads, the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared to an unmarked crosswalk. Further, on multilane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk alone (without other substantial improvements) was associated with a higher pedestrian crash rate (after controlling for other site factors) compared to an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multilane roads, compared to roads with no raised median. Older pedestrians had crash rates that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings on certain roads, such as adding traffic signals with pedestrian signals when warranted, providing raised medians, speed-reducing measures, and others.
-
safety effects of marked vs unmarked Crosswalks at uncontrolled locations executive summary and recommended guidelines
2002Co-Authors: Charles V Zegeer, H H Huang, J Stewart, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system, and they should, therefore be able to use this system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. All sites in this study had no traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, median type, speed limit, and other site variables. Poisson and negative binomial regressive models were used. The study results revealed that on two-lane roads, the presence of a marked crosswalk "alone" at an uncontrolled location was associated with no difference in pedestrian crash rate, compared to an unmarked crosswalk. Further, on multi-lane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk alone (without other substantial improvements) was associated with a higher pedestrian crash rate (after controlling for other site factors) compared to an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multi-lane roads, compared to roads with no raised median. Older pedestrians had crashes that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings on certain roads, such as adding traffic signals with pedestrian signals when warranted, providing raised medians, speed-reducing measures, and others.
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations analysis of pedestrian crashes in 30 cities
Transportation Research Record, 2001Co-Authors: Charles V Zegeer, J Stewart, Herman F Huang, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system and they should, therefore, be able to use the system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. None of the sites in this study had a traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, type of median, speed limit, and other site variables. Poisson and negative binomial regressive models were used. Study results revealed that on two-lane roads the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared with an unmarked crosswalk. Further, on multilane roads wi...
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations analysis of pedestrian crashes in 30 cities with discussion and closure
Transportation Research Record, 2001Co-Authors: Charles V Zegeer, J Stewart, Herman F Huang, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system and they should, therefore, be able to use the system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. None of the sites in this study had a traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, type of median, speed limit, and other site variables. Poisson and negative binomial regressive models were used. Study results revealed that on two-lane roads the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared with an unmarked crosswalk. Further, on multilane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk was associated with a higher pedestrian crash rate (after controlling for other site factors) compared with an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multilane roads, compared with roads without a raised median. Older pedestrians had crashes that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings, including adding traffic signals (with pedestrian signals) when warranted, providing raised medians, and implementing speed-reducing measures.
Peter Lagerwey - One of the best experts on this subject based on the ideXlab platform.
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations final report and recommended guidelines
2005Co-Authors: Charles V Zegeer, H H Huang, Peter Lagerwey, Richard J Stewart, John Feaganes, B J CampbellAbstract:Pedestrians are legitimate users of the transportation system, and they should, therefore, be able to use this system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. The purpose of this study was to determine whether marked Crosswalks at uncontrolled locations are safer than unmarked Crosswalks under various traffic and roadway conditions. Another objective was to provide recommendations on how to provide safer crossings for pedestrians. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 unmarked comparison sites. All sites in this study had no traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, median type, speed limit, and other site variables. Poisson and negative binomial regressive models were used. The study results revealed that on two-lane roads, the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared to an unmarked crosswalk. Further, on multilane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk alone (without other substantial improvements) was associated with a higher pedestrian crash rate (after controlling for other site factors) compared to an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multilane roads, compared to roads with no raised median. Older pedestrians had crash rates that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings on certain roads, such as adding traffic signals with pedestrian signals when warranted, providing raised medians, speed-reducing measures, and others.
-
SAFETY ANALYSIS OF MARKED VS UNMARKED Crosswalks IN 30 CITIES
2003Co-Authors: C Zegeer, C T Esse, J R Stewart, H H Huang, Peter LagerweyAbstract:Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of five years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. All sites in this study had no traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, median type, speed limit, and other site variables. Poisson and negative binomial regressive models were used. The study results revealed that on two-lane roads, the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared to an unmarked crosswalk. Further, on multi-lane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk alone (without other safety enhancements) was associated with a higher pedestrian crash rate (after controlling for other site factors) compared to an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multi-lane roads, compared to roads with no raised median. Older pedestrians had crashes that were over-represented relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings, such as adding traffic signals (with pedestrian signals) when warranted, providing raised medians, improving nighttime lighting, speed-reducing measures, and others.
-
safety effects of marked vs unmarked Crosswalks at uncontrolled locations executive summary and recommended guidelines
2002Co-Authors: Charles V Zegeer, H H Huang, J Stewart, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system, and they should, therefore be able to use this system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. All sites in this study had no traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, median type, speed limit, and other site variables. Poisson and negative binomial regressive models were used. The study results revealed that on two-lane roads, the presence of a marked crosswalk "alone" at an uncontrolled location was associated with no difference in pedestrian crash rate, compared to an unmarked crosswalk. Further, on multi-lane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk alone (without other substantial improvements) was associated with a higher pedestrian crash rate (after controlling for other site factors) compared to an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multi-lane roads, compared to roads with no raised median. Older pedestrians had crashes that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings on certain roads, such as adding traffic signals with pedestrian signals when warranted, providing raised medians, speed-reducing measures, and others.
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations analysis of pedestrian crashes in 30 cities
Transportation Research Record, 2001Co-Authors: Charles V Zegeer, J Stewart, Herman F Huang, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system and they should, therefore, be able to use the system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. None of the sites in this study had a traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, type of median, speed limit, and other site variables. Poisson and negative binomial regressive models were used. Study results revealed that on two-lane roads the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared with an unmarked crosswalk. Further, on multilane roads wi...
-
safety effects of marked versus unmarked Crosswalks at uncontrolled locations analysis of pedestrian crashes in 30 cities with discussion and closure
Transportation Research Record, 2001Co-Authors: Charles V Zegeer, J Stewart, Herman F Huang, Peter LagerweyAbstract:Pedestrians are legitimate users of the transportation system and they should, therefore, be able to use the system safely. Pedestrian needs in crossing streets should be identified, and appropriate solutions should be selected to improve pedestrian safety and access. Deciding where to mark Crosswalks is only one consideration in meeting that objective. This study involved an analysis of 5 years of pedestrian crashes at 1,000 marked Crosswalks and 1,000 matched unmarked comparison sites. None of the sites in this study had a traffic signal or stop sign on the approaches. Detailed data were collected on traffic volume, pedestrian exposure, number of lanes, type of median, speed limit, and other site variables. Poisson and negative binomial regressive models were used. Study results revealed that on two-lane roads the presence of a marked crosswalk alone at an uncontrolled location was associated with no difference in pedestrian crash rate, compared with an unmarked crosswalk. Further, on multilane roads with traffic volumes above about 12,000 vehicles per day, having a marked crosswalk was associated with a higher pedestrian crash rate (after controlling for other site factors) compared with an unmarked crosswalk. Raised medians provided significantly lower pedestrian crash rates on multilane roads, compared with roads without a raised median. Older pedestrians had crashes that were high relative to their crossing exposure. More substantial improvements were recommended to provide for safer pedestrian crossings, including adding traffic signals (with pedestrian signals) when warranted, providing raised medians, and implementing speed-reducing measures.