Road User Behavior

Independent and Interactive Association of Reported Impairment in Fatal Crashes Among Young California Drivers: A Cross-Sectional Analysis

Ainsley Lotito
Federico E. Vaca
Melody S. Li
Siwei Hu
Linda Hill
Julia Griswold
Kaigang Li
2026
Objective To examine the independent and combined associations of reported alcohol, drug, and fatigue involvement with crash fatality among young drivers in California. Methods Using 2016-2024 injury crash data from the University of California, Berkeley Transportation Injury Mapping System, we performed logistic regression to examine the association between reported driver impairment and crash fatality among drivers aged 15-24. Additive interaction was assessed using binary impairment indicators and interaction terms. Relative excess risk due to interaction (RERI) and 95% confidence...

California Traffic Safety Survey 2026

Ewald, Katrin
Wasserman, Lisa
2026

The Traffic Safety Public Opinion Study is conducted annually for the California Office of Traffic Safety (OTS) and the Safe Transportation Research and Education Center at UC Berkeley (SafeTREC). Eligible participants were California drivers aged 18 years and older. As in previous years, predetermined quotas were established by age and gender; however, the 2026 study used more detailed age categories aligned with U.S. Census data. For the 2026 version of the Traffic Safety Public Opinion Study, a substantially larger cross-section of 10,014 drivers were surveyed between June and July 2026...

New Release: 2022 SafeTREC Traffic Safety Fact Sheets

September 12, 2022
Submitted by Lisa Peterson
2022 SafeTREC Traffic Safety Fact Sheets feature recent data on some of California's most pressing traffic safety issues to help inform future road safety efforts

UC Berkeley SafeTREC is excited to announce the release of the 2022 series of Traffic Safety Fact Sheets, which feature traffic safety data and trends at the national and state level on a variety of road safety topics. This series also highlights the Safe System approach to road safety, which the United States Department of Transportation...

SafeTREC Traffic Safety Facts: Emergency Medical Services

September 20, 2018
SUBMITTED BY LISA PETERSON

Welcome back to the SafeTREC Traffic Safety Facts blog series! This summer, we have featured recent data on some of California's most pressing traffic safety issues. Today, we will wrap up the Series - for now! - and highlight the facts on emergency medical services.

We hope you have enjoyed exploring our traffic safety findings! Stay tuned for more posts in the series. And in case you missed any of the prior posts, check out the fact sheets on:

Alcohol-Impaired Driving...

SafeTREC Traffic Safety Facts: Seat Belt Use

September 18, 2018
SUBMITTED BY LISA PETERSON

Welcome back to the SafeTREC Traffic Safety Facts blog series! Each day this week we will feature recent data on some of California's most pressing traffic safety issues. Today, we will be highlighting the facts on seat belt use.

In case you missed them, check out the fact sheets on:

Alcohol-Impaired Driving Aging Road Users Bicycle Safety...

SafeTREC Traffic Safety Facts: Drug-Involved Driving

September 19, 2018
SUBMITTED BY LISA PETERSON

Welcome back to the SafeTREC Traffic Safety Facts blog series! Each day this week we will feature recent data on some of California's most pressing traffic safety issues. Today, we will be highlighting the facts on drug-involved driving.

In case you missed them, check out the fact sheets on:

Alcohol-Impaired Driving Aging Road Users Bicycle Safety...

SafeTREC Traffic Safety Facts: Speeding-Related Collisions

September 17, 2018
SUBMITTED BY LISA PETERSON

Welcome back to the SafeTREC Traffic Safety Facts blog series! Each day this week we will feature recent data on some of California's most pressing traffic safety issues. Today, we will be highlighting the facts on speeding-related collisions.

In case you missed them, check out the fact sheets on:

Alcohol-Impaired Driving Aging Road Users Bicycle Safety...

New release: California Active Transportation Data Portal for pedestrian, bicyclist, micromobility count data

September 30, 2025
Submitted by Karen Nguyen Vo

Home page of the CAT Data Portal

UC Berkeley SafeTREC has launched the California Active Transportation Data Portal (CAT Data Portal), a platform to collect, store, and visualize bicyclist, pedestrian, wheelchair, and other...

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...

The Goal of Road Safety in the Safe Systems Context

Fortin, Garrett
McMillan, Tracy
Grembek, Offer
Cooper, Jill F.
2018

Safe Systems is an approach to road safety that envisions the elimination of fatal and serious injuries and seeks to provide both a theoretical framework and practical roadmap for accomplishing such an ambitious goal. The Safe Systems approach involves a paradigm shift from traditional approaches to road safety planning and responsibility. This fact sheet provides an overview of the Safe Systems Approach and how it relates to both current road safety practice and initiatives such as Vision Zero. Read the full SafeTREC...