Data collection

Street Story: A platform for community engagement

Street Story

Street Story is a community engagement platform provided by UC Berkeley SafeTREC in English and Spanish that allows residents, community groups, and agencies to collect information about transportation crashes, near misses, general hazards, and safe locations to travel. The tool is free to use, anonymous, and publicly accessible. Street Story is not a...

Share your feedback now in the Pedestrian Level of Traffic Stress National Survey

June 20, 2025
Submitted by Karen Nguyen Vo

The Center for Pedestrian and Bicyclist Safety (CPBS) team at the University of Wisconsin, Milwaukee has launched a Pedestrian Level of Traffic Stress (PLTS) National Survey, where survey results will be used to help refine the PLTS, a tool that transportation agencies use to rate how comfortable pedestrians feel on specific roadways.

The survey aims to gather pedestrians’ perceived stress levels around...

California Traffic Safety Survey 2025

Ewald, Katrin
Wasserman, Lisa
2025

The 2025 Traffic Safety Public Opinion Study was conducted for the California Office of Traffic Safety (OTS) and the Safe Transportation Research and Education Center of UC Berkeley (SafeTREC). The findings of the 2025 Study are based on a sample size and eligibility criteria similar to previous years of data collection. A total of 2,319 responses were collected in April and May 2025 using an online selfadministered survey. Similar to previous years of the study, the survey panelists were provided through Marketing Services Group, a commercial sample and panel vendor.

The survey...

Evaluation of Wet Weather Accident Causation Criteria

Oh, Soonmi
Ragland, David R.
Chan, Ching-Yao
2008

This report documents findings from analysis of traffic collision data from sites that display high collision rates only under wet pavement conditions. These sites were selected using Caltrans safety engineers’ field reports, Wet Table C “investigation required” locations, and a new approach called Continuous Risk Profile (CRP). The geometric features at the sites were studied via field visits and review of as-built plans. Rapid spatial changes (i.e., vertical and horizontal curve in short distance), narrower lane width, lack of median, and wider total freeway width were some of the...

Drivers, Pedestrians, and Cyclists in California Want Complete Streets: Comparison of Results from Roadway Design Surveys of Pedestrians, Drivers, Bicyclists, and Transit Users in Northern and Southern California

Sanders, Rebecca L.
Griffin, Ashleigh
MacLeod, Kara E.
Cooper, Jill F.
2014

This paper compares findings from two recent surveys on roadway design preferences among pedestrians, drivers, bicyclists, and public transit users along major urban corridors in the metro areas of San Francisco and Los Angeles. Sponsored by the California Department of Transportation (DOT), the research explored design preferences that could increase perceived traffic safety, walkability, bikability, and economic vitality along urban arterials. Results from intercept surveys showed that roadway users desire similar design features along the test corridors, which carry 25,000-40,000...

SafeTREC's Liza Lutzker to present at 2025 SER Annual Meeting

May 29, 2025
Submitted by Lisa Peterson

UC Berkeley SafeTREC research data analyst Liza Lutzker will be presenting "Trends and disparities in pedestrian injuries and fatalities in hit-and-run crashes" in a poster session at the 2025 Society for Epidemiologic Research (SER) Annual Meeting on June 11th, 2025 in Boston, Massachusetts. This presentation draws from a current research project for the Center for Pedestrian and Bicyclist Safety (CPBS) that is examining recent trends and risk factors in pedestrian fatalities and injuries in hit-and-run...

Creating an inclusive bicycle level of service: Virtual bicycle simulator study

March 26, 2025
Submitted by Lisa Peterson
New report explores the benefits and limitations of using a VR environment to assess individuals’ bike infrastructure preferences

A new report by UC Berkeley Safe Transportation Research and Education Center (SafeTREC) co-authored by Julia Griswold, Edna Aguilar and Md. Mintu Miah, "Creating an inclusive bicycle level of service: Virtual bicycle simulator study" aims to assess how virtual reality (VR) technology can be used to gather user feedback on a variety of bicycling...

Creating an Inclusive Bicycle Level of Service: Virtual Bicycle Simulator Study

Griswold, Julia B.
Aguilar, Edna
Wang, Han
Miah, MD Mintu
2025

Bicycle level of service (BLOS) is an essential performance measure for transportation agencies to monitor and prioritize improvements to infrastructure, but existing measures do not capture the nuance of facility differences on the state highway system. However, with the advancements in virtual reality (VR) technology, a VR bicycle simulator is an ideal tool to safely gather user feedback on a variety of bicycling environments and conditions. This research explored the benefits and limitations of using a V...

A Multidimensional Clustering Algorithm for Studying Fatal Road Crashes

Fishbain, Barak
Grembek, Offer
2014

Road fatalities are rare outcomes of events that occur in a small time-space region. Although the exact chain of events for each fatality is unique, there are inherent similarities between road fatalities. The science of road safety is dedicated to identifying such similarities, mainly using statistical analysis tools. Researchers typically analyze patterns that emerge over space, such as hot-spot studies, or patterns that emerge over time, such as before-after studies. Traffic research enumerates 84 parameters that characterize a road fatality. A vast number of papers have tried to...

Develop Methods to Reduce or Prevent Backing Crashes

Cooper, Douglas L.
Duffy, Sarah
Orrick, Phyllis
Ragland, David R.
2009

Workplace motor vehicle incidents at Caltrans are a significant cause of injuries, employee lost time, and property damage. Because backing crashes are major contributors to motor vehicle incidents, identifying and promoting methods of reducing backing accidents is a top priority. According to internal Caltrans’ data, 92.3% of workplace backing crashes were preventable by the driver. Backing crashes are the single largest category of preventable crashes, representing 30% of preventable crashes in the Caltrans fleet. From 1998 through 2007, preventable backing crashes cost Caltrans at least...