Fresno State Transportation Institute

DUI Crashes in the Central Valley:

Trends, Factors, & Solutions

Researching DUI Crash trends and patterns and implementing effective prevention strategies in California's Central Valley.

DUI Project Banner explaining that by understanding trends and factors you can create solutions and prevent DUI Fatal Crashes

Project Overview:

The Fresno State Transportation Institute (FSTI), in partnership with the Central California Public Health Consortium (CCPHC), is conducting a regional research study of DUI-related fatalities across 12 Central California counties: Calaveras, Fresno, Kern, Kings, Madera, Mariposa, Merced, San Benito, San Joaquin, Stanislaus, Tulare, and Tuolumne. The analysis uses Fatality Analysis Reporting System (FARS) data from 2010 to 2023 to characterize the spatial distribution, temporal patterns, and underlying factors associated with fatal DUI crashes in the region.

The study evaluates crash circumstances at a detailed level, some of which include, but are not limited to, driver demographics, prior history, roadway characteristics, driving conditions, speed involvement, and lighting and environmental context. Geospatial methods are applied to delineate high-risk roadway segments, identify persistent and emerging clusters, and assess whether crash involvement is local or non-local in origin.

Building on these findings, the project will expand to include a predictive analytics framework to identify locations and conditions associated with future DUI-related fatalities. The intent is to support a transition from reactive responses to targeted, preventive strategies, enabling more effective safety interventions and resource allocation.

The project is structured to support coordinated regional implementation. Through the Traffic Safety Task Force, local health departments, law enforcement, emergency medical services, transportation agencies, and community organizations can jointly interpret findings and align response strategies across jurisdictions. The next phase includes pilot deployment of the predictive model in selected counties, followed by expansion across the region.

A picture of the Central Valley and the counties involved in the study.

Graphic showing that DUI fatality rates in California’s Central Valley are about 2.5 times higher than the state average. A line chart from 2014 to 2023 shows Central Valley rates consistently above the state and slightly increasing over time. Key points highlight consistently higher risk, a widening safety gap, and the need for intervention. FSTI will develop a modeling tool top address this and prevent this.

Graphic showing driver risk factors: 46% had prior violations, 16% had a previous crash, and 12% had a prior DWI conviction. Additionally, 34% of drivers were speeding, and DUI drivers averaged 23 mph over the speed limit. Shows how big an issue this is in the California's Central Valley

Graphic showing Central Valley DUI fatalities are higher than the state, especially at night. Most fatalities occur in rural areas (54.1%), suggesting higher risk outside urban areas compared to contrary belief. Weekends and evening to early morning hours (6 PM to 2 AM) show the highest risk, likely linked to increased social activity. A heatmap highlights these peak times. The takeaway is that we can prioritize safety interventions and that some patterns are predictable and others are not.

 

One Pager Central Valley Example

Explore County-Level Insights:

These findings and additional analyses have been compiled into detailed county one-pagers for all regions included in the study. Each profile presents driver demographics, prior history, crash characteristics, and roadway and environmental conditions to provide detailed, data-driven insights at the county level. Counties included are:

• Calaveras                         • Merced

• Fresno                              • San Benito

• Kern                                  • San Joaquin

• Kings                                • Stanislaus

• Madera                             • Tulare

• Mariposa                          • Tuolumne
View County One-Pagers

Collective Collaborative Showcase

Fresno State Transportation Institute Project Team:
Principal Investigators:
  • Alexis Perez, Graduate Civil Engineer at Lyles College of Engineering
  • Aly Tawfik, Director of the Fresno State Transportation Institute & Professor of Transportation and Systems Engineering in the Lyles College of Engineering
Project Partners Central California Public Health Consortium:
Gallery Image of the Project Team

 

Project Information

For questions about the research study, contact:

Dr. Aly Tawfik
Director of FSTI & Professor of Civil Engineering in the Lyles College of Engineering
tawfik@csufresno.edu
559.278.2500

 

Safety Traffic Force Participation

To get involved in the Safety Traffic Force, pilot counties, or discussions, contact:

Alyssa Kennett
Director Of CCPHC & OTS Grant PI
ccphc@mail.fresnostate.edu
559.228.2150