Data collection

Space Syntax: The Role of Urban Form in Cyclist Route Choice in Central London

Raford, Noah
Chiaradia, Alain
Gil, Jorge
2007

This paper presents a new method for forecasting cyclist volume and route choice based on space syntax techniques for urban analysis. Space syntax has been shown to correlate strongly with pedestrian and vehicular trips in a number of international studies, but little research to date has focused on the role of urban form and street network design in cyclist route choice. This paper addresses this gap by analyzing the distribution of cycling trips in the central London area, focusing on a sample of work-based commuting trips. A sample of 423 cyclists from 50 organizations was combined with...

Safe Routes to School Safety and Mobility Analysis

Orenstein, Marla R.
Gutierrez, Nicolas
Rice, Thomas M.
Cooper, Jill F.
Ragland, David R.
2007

This report evaluates the SR2S program for a number of mandated issues: (i) The effectiveness of the program in reducing crashes, injuries and fatalities involving children in the vicinity of the projects; (ii) The impact of the program on levels of walking and bicycling to school; and (iii) The safety benefits of the program in comparison with other highway safety programs.

San Pablo Avenue Pedestrian Signal Timing Optimization

Nguyen, Ahn
Ragland, David R.
2007

The focus of this study is to quantify the sufficiency of “Flashing Don’t Walk” (FDW) intervals at signalized pedestrian crossings in the San Pablo Avenue (SPA) corridor in Northern California. Our goal is to determine if pedestrian signal intervals on the SPA corridor can be optimized in a way that makes the pedestrian crossing environment safer and more comfortable for all pedestrians without diminishing vehicular throughput. This study provides a corridor-wide as well as a city-bycity assessment of FDW intervals on the SPA corridor. We suggest a possible tool to assist traffic control...

What They Don’t Know Can Kill Them

Mitman, Meghan F.
Ragland, David R.
2007

Traffic safety researchers have long argued that driver behavior outweighs physical elements (such as road design) as a causal factor in motor vehicle collisions. A fundamental causal component of pedestrian-vehicle collisions is also behavior—that of the driver and that of the pedestrian. One determinant of this behavior may be whether the driver, the pedestrian, or both understand the motor vehicle code, which demarcates right-of-way in pedestrian-vehicle interactions. That is, inappropriate or unlawful behavior may occur because the law is not understood or is misunderstood. Previous...

Changes in Driver Behavior Resulting from Pedestrian Countdown Signals

Huey, S. Brian
Ragland, David R.
2007

This paper explores the effects that pedestrian countdown signals have on driver behavior. Observations of two intersections, one with pedestrian signals and one without, were made focusing specifically on driver behavior during the amber and red phases. It was found that drivers at the pedestrian countdown intersection were less likely to enter the intersection at the end of the amber phase than those at the traditional pedestrian signal intersection. It was also found that drivers at the intersections with traditional pedestrian signals exhibited different stopping behavior near the...

Pedestrian Counting Methods at Intersections: a Comparative Study

Diogenes, Mara Chagas
Greene-Roesel, Ryan
Arnold, Lindsay S.
Ragland, David R.
2007

Resources for implementing countermeasures to reduce pedestrian collisions in urban centers are usually allocated on the basis of need, which is determined by risk studies. They commonly rely on pedestrian volumes at intersections. The methods used to estimate pedestrian volumes include direct counts and surveys, but few studies have addressed the accuracy of these methods. This paper investigates the accuracy of three common counting methods: manual counts using sheets, manual counts using clickers, and manual counts using video cameras. The counts took place in San Francisco. For the...

Rail Crossings: A Strategy to Select Countermeasure Improvements for Rail-Highway Crossings in California

Cooper, Douglas L.
Ragland, David R.
2007

Rail crossing crashes have declined in the past 30 years, both nationally and in California. This is largely attributed to the closing of a large number of crossings as well as the deployment of a wide range of countermeasures, including signal systems, gating and grade separation programs. However, the number of crashes and subsequent injuries and deaths is still unacceptably high. Rail crossings provide different levels of warnings from four-quadrant gates down to stop signs. To understand how the state of California can best utilize state and federal funding available through SAFETEA-LU...

A 3D Computer Simulation Test of the Leibowitz Hypothesis

Barton, Joseph E.
Cohn, Theodore E.
2007

Do large objects appear to approach more slowly than smaller objects traveling at the same speed? If so then this might help explain the inordinately high accident rates involving large vehicles such as buses and trains. To test this, this study constructed an experiment using a 3D visual simulator in which different sized textured spheres approached at different speeds. We found that observers consistently judged the smaller sphere to be the faster, even in cases where the larger sphere was traveling at up to twice the speed of the smaller. Analysis of these results suggests that the...

Evaluation of Countermeasures: A Study on the Effect of Impactable Yield Signs Installed at Intersections in San Francisco

Banerjee, Ipsita
Ragland, David R.
2007

The present study evaluated the effect of impactable signs that used the yield-symbol as approved by the National Committee on Uniform Traffic Control Devices (NCUTCD) in the 2003 Manual of Uniform Traffic Control Devices (MUTCD). Impactable yield signs are low-cost signs constructed of flexible material. The signs were installed in the medians adjacent to crosswalks at selected non-signalized intersections to instruct drivers to yield the right-of-way to pedestrians. This paper examines the effect on safety characteristics of the intersections of these signs at three stop-sign controlled...

Child Restraint Use: Workbook and Guide for Evaluating Community-based Programs

Ragland, David R.
Geyer, Judy A.
Cooper, Jill F.
2003

The leading cause of injury and death for children in California is motor vehicle crashes. To prevent these needless tragedies, the California Office of Traffic Safety (OTS), through the Business, Transportation and Housing Agency, funds child passenger safety programs throughout the state. This workbook is designed to be used by these local programs to 1) evaluate the impact of their activities on child restraint use, 2) evaluate results to improve or modify the programs as needed, and 3) meet contractual evaluation requirements. Program evaluations can be difficult for local programs due...