San Pablo Avenue Pedestrian Signal Timing Optimization

2019

16. ABSTRACT The conflict between pedestrians using crosswalk and turning traffic at intersections poses a safety risk to pedestrians. To mitigate the risk, Caltrans engineers conceived a new safety feature for pedestrian signal – Yellow Pedestrian Border (YPB). YPB is a new feature that a yellow LED light border is added around the pedestrian signal (See Picture 1). YPB is a supplement to the existing standard pedestrian signal display, which provides a direct feedback to pedestrians who push the crosswalk button. Furthermore, YPB also makes the pedestrian signal more visible, which alerts drivers that the pedestrian signal is about to serve a crosswalk. A preliminary study conducted in Redding, CA, demonstrated the benefits of YPB and its impact on pedestrian safety. This research is an extension to the preliminary study, which aims at testing and assessing the YPB safety benefits at different locations and traffic conditions.

2018

Intersections are a critical location for pedestrian safety and also have a role in traffic operational efficiency. To improve pedestrian safety, the Exclusive Pedestrian Phase (EPP) was developed in the 1960s, which adds a phase entirely for pedestrian movements without any conflict with vehicles. The EPP is believed to be the safest type of pedestrian protection and has been installed in many places instead of Concurrent Pedestrian Phase (CPP). CPP allows pedestrians to cross in parallel to moving vehicles which allows conflicts between turning vehicles and pedestrians. The research hypothesis was to explore whether EPP has encouraged pedestrian non-compliance (crossing without the walk signal) and conflicting pedestrians (crossing in the direct path of a vehicle) or not and what the impact of such behavior is on vehicular intersection delay. This pedestrian behavior may lead to a less safe situation for pedestrians. The research compared 8 pairs of intersections representing both...

2015

The goal of this research effort was to improve pedestrian safety at urban and suburban crossing locations by identifying and evaluating low- to medium-cost pedestrian treatments. The treatments were to have the potential to reduce pedestrian crashes at both midblock and intersection locations. While several treatments were considered during early efforts of this project, later tasks focused on the rectangular rapid-flashing beacon (RRFB). The RRFB has received extensive national attention because of high yielding rates observed at multiple installations, and several studies have found increased driver yielding after installing this device. The key research effort for this study included a closed-course study and an open-road study. The objectives of the closed-course study were as follows: (1) Determine whether the shape, size, and placement of flashing beacons/light-emitting diodes (LEDs) affect sign legibility distances and object detection. (2) Determine driver ratings of disabi...

Transportation Research Record, 1984

The purpose of this study was to develop and evaluate innovative pedestrian sign and signal alternatives, particularly those that indicate the clearance interval (in place of the flashing DONT WALK message) and those that warn pedestrians of possible turning vehicles (instead of the flashing WALK message). A total of 41 alternatives were developed, and the 8 judged most promising were evaluated at several sites within 5 U.S. cities. The alternatives were evaluated using before-and-after studies of pedestrian violations and various types of pedestrian-vehicle conflicts. Based on the results of the Z-test analyses of observations at the study sites, several alternatives were recommended for inclusion in the Manual on Uniform Traffic Control Devices for application at intersections with pedestrian safety problems. These included the WALK WITH CARE signal indication, a sign for motorists stating YIELD TO PEDESTRIANS WHEN TURNING (regulatory sign), a pedestrian warning sign stating PEDES...

1994

Abstract: The traditional approach to reduce accidents at intersections has been to install traffic control devices. However, it has not been established that installation of such devices as signals, signs, or pavement markings, substantially improves pedestrian safety. On the contrary, empirical investigations have indicated that these devices tend to create a false sense of security. The major criteria used in installing these devices are vehicular volumes, pedestrian volumes, and engineering judgment. The compliance with these devices is, ...

Pedestrian countdown timers are becoming common at urban and suburban intersections.

Transportation Research Record, 1982

The purpose of this study was to determine whether pedestrian accidents are significantly affected by the presence of pedestrian signal indications and by different strategies for signal timing. Data related to pedestrian accidents, intersection geometrics, traffic and pedestrian volumes, roadway environment, and signal operation were collected for 1297 traffic-signalized intersections in 15 cities throughout the United States. The data were analyzed by using various statistical tests, which included branching analysis, correlation analysis, chi-square analysis, and the analysis of variance and covariance. The results showed no significant difference in pedestrian accidents between intersections that had standard-timed (concurrent walk) pedestrian signals compared with intersections that had no pedestrian signal indications. In addition, exclusive-timed locations were found to be associated with lower pedestrian accident experience for intersections with moderate-to-high pedestrian ...

WIT Transactions on the Built Environment, 2003

A research-team has investigated crossing activities of pedestrians at 10 signalized intersections located in Montreal and 10 signalized intersections in Toronto. This paper is concerned at determining the physical and environmental characteristics of signalized intersections and pedestrian behavior. The dependent variable was defined as whether or not the pedestrian obeyed the green light indicator. The relationship between pedestrian behavior and the physical and environmental characteristics of signalized intersections has been performed through logistic regression. Results indicate that some physical and environmental characteristics at signalized intersections such as a refuge island improve pedestrian behavior, whereas a wider street is associated with an increase in the disobedience of the traffic light. The analysis performed in this work cannot determine if the difference in pedestrian behavior between Montreal and Toronto can be solely attributed to the physical environment of signalized intersections.

2016

Most pedestrian crashes occur at crosswalks and/or within their vicinity. It may be caused by violations of traffic and pedestrian control regulations or inattention by drivers and pedestrians. The ...

2006

A recent research project jointly sponsored by the Transit Cooperative Research Program and the National Cooperative Highway Research Program had two main objectives: (a) recommend selected engineering treatments to improve safety for pedestrians crossing highvolume, high-speed roadways at unsignalized intersections, in particular those served by public transportation; and (b) recommend modifications to the Manual on Uniform Traffic Control Devices [MUTCD] pedestrian traffic signal warrant. The research team developed guidelines that can be used to select pedestrian crossing treatments for unsignalized intersections and midblock locations (Guidelines for Pedestrian Crossing Treatments). Quantitative procedures in the Guidelines use key input variables (such as pedestrian volume, street crossing width, traffic volume, etc.) to recommend one of four possible crossing treatment categories. The research team developed and presented recommendations to revise the MUTCD pedestrian warrant for traffic control signals to the National Committee on Uniform Traffic Control Devices. In accomplishing the two main study objectives, the research team also developed useful supporting information such as the findings from the field studies on walking speed and motorist compliance. Pedestrian walking speed recommendations were 3.5 ft/s (1.07 m/s) for general population and 3.0 ft/s (0.9 m/s) for older or less able population. Motorist compliance (yielding or stopping where required) was the primary measure of effectiveness for engineering treatments at unsignalized roadway crossings. The study found that the crossing treatment does have an impact on motorist compliance, and other factors influencing the treatment effectiveness were number of lanes being crossed and posted speed limit.