SafeTREC

Association between Roadway Intersection Characteristics and Pedestrian Crash Risk in Alameda County, California

Schneider, Robert J.
Diogenes, Mara Chagas
Arnold, Lindsay S.
Attaset, Vanvisa
Griswold, Julia
Ragland, David R.
2010

Each year from 1998 to 2007, an average of approximately 4,800 pedestrians were killed and 71,000 pedestrians were injured in United States traffic crashes. Because many pedestrian crashes occur at roadway intersections, it is important to understand the intersection characteristics that are associated with pedestrian crash risk. This study uses detailed pedestrian crash data and pedestrian volume estimates to analyze pedestrian crash risk at 81 intersections along arterial and collector roadways in Alameda County, California. The analysis compares pedestrian crash rates (crashes per 10,...

The Continuing Debate about Safety in Numbers—Data From Oakland, CA

Geyer, Judy
Raford, Noah
Ragland, David
Pham, Trinh
2005

The primary objective of this paper is to review the appropriate use of ratio variables in the study of pedestrian injury exposure. We provide a discussion that rejects the assumption that the relationship between a random variable (e.g., a population X) and a ratio (e.g., injury or disease per population Y/X) is necessarily negative. In the study of pedestrian risk, the null hypothesis is that pedestrian injury risk is constant with respect to pedestrian volume. This study employs a unique data set containing the number of pedestrian collisions, average annual pedestrian volume, average...

Dynamic Programming-based Pedestrian Hotspot Identification Approach

Medury, Aditya
Grembek, Offer
2014

Network screening techniques are widely used by state agencies to identify locations with high collision concentration, also referred to as hotspots. However, most of the research in this regard has focused on identifying highway segments that are of concern to automobile collisions. A major difference between pedestrian and automobile hotspots is that pedestrian-based conflicts are more likely to arise in localized regions, such as near intersections, mid-blocks, and/or other crossings, as opposed to along long stretches of roadway. Hence, in order to address this issue, a dynamic...

The Marked Crosswalk Dilemma: Uncovering Some Missing Links in a 35-Year Debate

Mitman, Meghan Fehlig
Ragland, David R.
Zegeer, Charles V.
2008

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...

Evaluation of an Urban Travel Training for Older Adults

Babka, Rhinna Jolris
Cooper, Jill F.
Ragland, David R.
2008

The size of the aging population in the United States is increasing, and transportation is critical to maintaining older adults mobility, independence, and quality of life. Travel training programs designed to increase individual knowledge are one way to encourage older adult use of fixed- route transit and improve the transportation options for older adults. The analysis conducted in this paper explores characteristics of travel-training participants in Alameda County, California in 2007-2008 and their knowledge and concerns regarding public transit. Specific issues addressed include...

High Visibility Enforcement Programs: California’s State and University Traffic Safety Partnership

Cooper, Jill F.
Kan, Irene
Cadet, Akilah
Rauch, Sharleen
Murphy, Christopher J.
2009

Traffic collisions are a leading cause of death and injury in California and the number one cause of death for people between the ages of one and 44. High-visibility enforcement programs (HVEs) are administered nationwide by the National Highway Traffic Safety Administration, and combine intensive enforcement of a particular traffic safety law with widespread media and public education campaigns. HVE programs have been shown to be effective in reducing alcohol-impaired driving and promoting seat belt use. A major challenge in implementing HVEs, however, exists among local police agencies,...

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...

An Intensive Pedestrian Safety Engineering Study Using Computerized Crash Analysis

Ragland, David R
Markowitz, Frank
MacLeod, Kara E
2003

Over the past year, the San Francisco Department of Parking and Traffic (DPT) conducted an intensive pedestrian-safety engineering study, the PedSafe Study. PedSafe was funded by the Federal Highway Administration (FHWA)*, which also funded companion studies in Las Vegas and Miami. The study was designed to analyze pedestrian injuries by zones (i.e., neighborhoods or districts) and to identify those most amenable to prevention efforts. The DPT expects to utilize the methodology and information from the PedSafe study to help shape a citywide pedestrian master plan. This paper describes the...

Gap acceptance for vehicles turning left across on-coming traffic: Implications for Intersection Decision Support design

Ragland, David R
Arroyo, Sofia
Shladover, Steven E.
Misener, James A.
Chan, Ching-Yao
2006

A left-turning vehicle (Subject Vehicle, SV) attempting to cross the path of an oncoming vehicle (Principal Other Vehicle, POV) at an intersection typically does not have the right of way. The main task of the SV driver is to find an adequate opportunity in opposing traffic to initiate the left-turn maneuver. To reduce the probability of a conflict, warning systems, such as Intersection Decision Support (IDS) systems, are being developed. These systems alert drivers of SV vehicles attempting to negotiate a left turn about traffic approaching from the opposite direction. The current paper (...

The Effects of Transportation Corridor Features on Driver and Pedestrian Behavior and on Community Economic Vitality: Final Study Report

Sanders, Rebecca L. PhD
Griffin, Ashleigh MS, MCP
MacLeod, Kara E. MHP
Cooper, Jill F. MSW
Ragland, David R. PhD, MPH
2012

This report presents the results from a multiyear effort to develop and test performance measures for evaluating the impact of landscaping and roadside features on pedestrian and bicyclist safety and mobility and economic vitality for Caltrans’ urban arterial network. The first phase of the study was a literature review, and the second phase focused on developing performance measures. The third and fourth phases focused on testing the proposed performance measures consisting of an infrastructure analysis, policy review, safety analysis and a pedestrian and bicyclist intercept survey on two...