Safety

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) approach...

Limitations of Data on Cell Phone Involvement in Collisions: A Case Study of California

Griswold, Julia B.
Grembek, Offer
2014

With the increasing prevalence of mobile technology and high-profile crashes bringing attention to distracted driving, data on cell phone involvement in collisions is critical for understanding the extent of the problem, examining the effectiveness of policies, and developing interventions to improve safety. Some limitations of existing data have been previously identified, but this paper examines the specific case of California’s collision data. Temporal, geographic, and jurisdictional trends are analyzed to identify the source and type of inconsistencies in the cell phone involvement...

Driver Behavior at Rail Crossings: Cost-Effective Improvements to Increase Driver Safety at Public At-Grade Rail-Highway Crossings in California

Cooper, Douglas L.
Ragland, David R
2007

This report examines conditions affecting vehicle-train collisions at rail crossings in California, and recommends effective countermeasures and implementation strategies. In doing so, the report helps meet California’s goal of efficiently utilizing state and federal funding available through SAFETEA-LU for increasing the safety at public at grade rail-highway crossings.

Sujin Lee

Postdoctoral Researcher
Safe Transportation Research and Education Center
SafeTREC

Sujin Lee is a postdoctoral scholar at the Safe Transportation Research and Education Center (SafeTREC) at UC Berkeley.

Her current research focuses on examining how regional characteristics and safety measures contribute to reducing traffic crashes and creating safer transportation environments. She is also interested in the intersection of travel demand and urban attributes, using insights from multifaceted datasets to promote sustainable urban development and enhance travel demand management.

She earned her Ph.D. (2024) and M.S. (2019) from the Graduate School of Mobility...

Pre-Intervention Assessment: UC Davis Medical Center and California Health Care Safety Net Institute Child Passenger Safety Initiative

Cooper, Jill
Ragland, David R
MacLeod, Kara E
Jameson, Wendy
2002

Proper use of child passenger safety (CPS) systems is highly effective in reducing injury and fatality in traffic crashes. While use of CPS systems is increasing, use is not universal, and there is a high level of improper use. The Child Passenger Safety Initiative is an innovative program to provide education and training in proper CPS system use to adults with children attending public hospitals and clinics. The initiative will provide education and resources to these adults. A pre-intervention baseline study with a sample of adults and children at four participating hospitals and...

Strategies for Reducing Pedestrian and Bicyclist Injury at the Corridor Level

Ragland, David R.
Grembek, Offer
Orrick, Phyllis
2011

Methods for identifying sites with potential for preventing traffic fatalities and injuries have been developed for vehicle-vehicle collisions. This study was funded by the California Department of Transportation (Caltrans) to develop methods for identifying sites where there is potential for significant reductions in pedestrian and bicyclist injury. Data from 1998-2007 from a 16.5-mile section of San Pablo Avenue (SR 123) in the San Francisco East Bay was used as a study area. Several approaches for identifying sites with high potential for reducing pedestrian and bicyclist injury were...

Estimating Pedestrian Accident Exposure: Automated Pedestrian Counting Devices Report

Bu, Fanping
Greene-Roesel, Ryan
Diogenes, Mara Chagas
Ragland, David R.
2007

Automated methods are commonly used to count motorized vehicles, but are not frequently used to count pedestrians. This is because the automated technologies available to count pedestrians are not very developed, and their effectiveness hasnot been widely researched. Moreover, most automated methods are used primarilyfor the purpose of detecting, rather than counting, pedestrians (Dharmaraju et al.,2001; Noyce and Dharmaraju, 2002; Noyce et al., 2006). Automated pedestrian counting technologies are attractive because they have the potential to reduce the labor costs associated with manual...

Evaluating Research on Data Linkage to Assess Underreporting of Pedestrian and Bicyclist Injury in Police Crash Data

Doggett, Sarah
Ragland, David R.
Felschundneff, Grace
2018

Traffic safety decisions are based predominantly on information from police collision reports. However, a number of studies suggest that such reports tend to underrepresent bicycle and pedestrian collisions. Underreporting could lead to inaccurate evaluation of crash rates and may under- or overestimate the effects of road safety countermeasures. This review examined ten studies that used data linkage to explore potential underreporting of pedestrian and/or bicyclist injury in police collision reports. Due to variations in definitions of reporting level, periods of study, and study...

The Association Between Health Problems and Driver Status Among Older Adults

MacLeod, Kara E.
Geyer, Judy A.
Satariano, William A.
Ragland, David R.
2004

Many health problems, especially those associated with older age, can have an impact on an individual’s mobility. This paper addresses how specific functional limitations and medical conditions may be associated with driving status, while controlling for age and gender. This paper uses baseline data (N=2025) from a longitudinal survey of adults, ages 55 and older, the Study of Physical Performance and Age-Related Changes in Sonomans (SPPARCS). For the 35 selected medical conditions and functional limitations, this report presents the prevalence, the relative “risk” ratio (i.e., the risk...

Intersection Decision Support Project: Taxonomy of Crossing-Path Crashes at Intersections Using GES 2000 Data

Ragland, David R.
Zabyshny, Aleksandr A.
2003

The Intersection Decision Support (IDS) Project is designed to reduce crossing-path (CP) crashes at intersections by providing crucial information to drivers that would help them avoid such crashes. Over the past decade, researchers have used the General Estimates System (GES, a representative sample of police-reported crashes in the US) and other data sources to develop a taxonomy of CP crashes and pre-crash scenarios as groundwork for crash-prevention efforts. The current study builds on and extends prior work by constructing a taxonomy of CP crashes using data from the 2000 GES and...