Motorized Vehicle Safety

Safety Performance of Experimental Pavement Types in California Using Before-and-After Comparisons

Oh, Soonmi
Ragland, David R.
Chan, Ching-Yao
2010

This study focused on safety performance of new pavement surface types. Open graded or coarse- textured roadway surfaces are advisable for high-speed, wet-weather traffic conditions. They provide drainage relief at the tire-pavement interface, reduce the steepness of the speed gradient, decrease the likelihood of hydroplaning, minimize splash and spray, reduce the glare from wet pavements, and improve high-speed skid resistance. Before-and-after comparisons using historical collision data from California Traffic Accident Surveillance and Analysis System (TASAS) were conducted to...

Driver and Pedestrian Behavior at Uncontrolled Crosswalks in the Tahoe Basin Recreation Area

Mitman, Meghan F.
Cooper, Douglas L.
DuBose, Brooke
2010

For more than thirty years, pedestrian safety studies have considered pedestrian-vehicle collision patterns and pedestrian and driver behavior at marked and unmarked crosswalks at uncontrolled crossings. Recent research in this area conducted by the UC Berkeley Traffic Safety Center [aka SafeTREC] on behalf of Caltrans, and summarized in a 2008 Transportation Research Record paper by Mitman et al., “The Marked Crosswalk Dilemma: Uncovering Some Missing Links in a 35-Year Debate,” was designed to fill key gaps in the literature by analyzing driver/pedestrian behavior and knowledge of...

Factors Associated with Hit-and-Run Pedestrian Fatalities and Driver Identification

MacLeod, Kara E.
Griswold, Julia B.
Arnold, Lindsay S.
Ragland, David R.
2010

Because hit-and-run crashes account for a significant share of pedestrian fatalities, a better understanding of these crashes will assist efforts to reduce pedestrian fatalities. Of the more than 48,000 pedestrian deaths that were recorded in the United States between 1998 and 2007 (Fatality Accident Reporting System [FARS]), 18.1% of them were the victims of hit-and-run crashes, and the percentage of fatal pedestrian hit-and-runs has been rising as the number of all pedestrian fatalities has decreased. Using FARS data on single pedestrian fatal victim crashes between 1998-2007,...

Problems With Vision Associated With Limitations or Avoidance of Driving in Older Populations

Satariano, William A.
MacLeod, Kara E.
Kohn, Theodore E.
Ragland, David R.
2004

Objectives. This report examines the role of (a) disease processes affecting vision, (b) reported troubles with vision, (c) physical symptoms affecting the eyes, and (d) objective measures in reported driving limitation due to problems with eyesight among older drivers.

Methods. Data for this study (N 1⁄4 1,840) were obtained from participants in a community-based study of aging and physical performance in people age 55 or older in the city of Sonoma, California. Each of 16 visual conditions was...

Addressing Inappropriate Driver Behavior at Rail-Highway Crossings

Cooper, Douglas L.
Ragland, David R.
2008

Driver behavior at rail highway crossings has been the subject of numerous studies, most of which show that violations are relatively commonplace. The focus of this paper will be on those drivers who drive around fully descended gates. Drivers commonly misjudge the speed and distance of trains. They must make a decision about the time remaining before the train arrives based on sensory signals as well as non-sensory factors such as expectations and motivation. At a gated crossing, where drivers have been alerted to the imminent danger by lowered gates, there is more to be gained by...

Analysis of Wet Weather Related Collision Concentration Locations: Empirical Assessment of Continuous Risk Profile

Oh, Soonmi
Chung, Koohong
Ragland, David R.
Chan, Ching-Yao
2009

The objective of the study described in this paper is to identify common site features that may contribute to high collision rates under wet pavement conditions. To minimize falsely identified high collision concentration locations (HCCL) in evaluating factors contributing to high collision rate, this study accessed the magnitude of false positives (i.e., identifying sites for safety improvements that should not have been selected) by comparing HCCLs identified by the existing conventional sliding moving window approach with the ones identified by the Continuous Risk Profile (CRP)...

Performance Measures for Complete, Green Streets: A Proposal for Urban Arterials in California

Sanders, Rebecca L.
Macdonald, Elizabeth
Anderson, Alia
2010

The California Department of Transportation (Caltrans or “Department”) manages more than 15,000 miles of state highways, ranging in scale and function from local streets to interstate highways. Historically, Caltrans has been governed by the principles of highway engineering, which focus on providing mobility to motorized vehicles. Over the past decade, however, the Department has joined in a national movement to better incorporate non-motorized transportation and community-level outcomes into its transportation decision-making framework, embodied by the approach known as "Complete...

Property Damage Crash Equivalency Factors for Solving the Crash Frequency-Severity Dilemma: Case Study on South Korean Rural Roads

Oh, Jutaek
Washington, Simon
Lee, Dongmin
2010

Safety interventions (e.g. median barriers, photo enforcement) and road features (e.g. median type and width) can influence crash severities, crash frequencies, or both. Both dimensions—crash frequency and crash severity—are needed to obtain a full accounting of road safety. Extensive literature and common sense both dictate that all crashes are not ‘created’ equal—with fatalities costing society more than 1000 times the cost of property damage only crashes. Despite this glowing disparity, the profession has not unanimously embraced or successfully defended a non-arbitrary severity...

Single-Vehicle Fatal Crash Prediction for Two-Lane Rural Highways in the Southeastern United States

Zhu, Hong
Dixon, Karen K.
Washington, Simon
Jared, David M.
2010

The rural two-lane highway in the Southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes and as such remains a focus of considerable safety research. The Georgia Department of Transportation spearheaded a regional fatal crash analysis to identify various safety performances on two-lane rural highways and offer guidance for identifying suitable countermeasures to mitigate fatal crashes. The fatal crash data used in this study were compiled from Alabama, Georgia, Mississippi, and South Carolina. The database, developed for an...

Impact of Traffic States on Freeway Collision Frequency

Yeo, Hwasoo
Jang, Kitae
Skabardonis, Alexander
2010

Freeway collisions are thought to be affected by traffic states. To reduce the number of collisions, the study to reveal how the traffic states influence collisions are required. Therefore, the purpose of the paper is to suggest a method to relate traffic states to collision frequency in freeway. We first defined section- based traffic phases showing traffic state of a section using upstream and downstream traffic states: free flow (FF), back of queue (BQ), bottleneck front (BN) and congestion (CT). Secondly, by integrating freeway collision data and traffic data from the California PeMS...