Motorized Vehicle Safety

Learning the representation of surrogate safety measures to identify traffic conflict

Jiajian Lu
Offer Grembek
Mark Hansen

Traffic conflict can be identified by the presence of evasive actions or the amount of temporal (spatial) proximity measures like time-to-collision (TTC). However, it is not enough to use only one kind of measures in some scenarios and it is hard to set a threshold for those measures. This paper proposed a method to identify traffic conflict by learning the representation of TTC and driver maneuver profiles with deep unsupervised learning and clustering the representations into traffic conflict and non-conflict clusters. We first trained a transformer encoder to encode sequences of...

California Traffic Safety Survey 2022: Speeding and Aggressive Driving Biggest Safety Concern

June 1, 2022

UC Berkeley SafeTREC is excited to release the 2022 California Traffic Safety Survey led by Ewald & Wasserman Research Consultants (E&W). This study was conducted on behalf of the California Office of Traffic Safety (OTS) and the Safe Transportation Research and Education Center (SafeTREC) at the University of California, Berkeley.

Speeding and Aggressive Driving Biggest Safety Concern

Speeding and aggressive driving was the biggest safety concern for California drivers (75.0% of surveyed...

New Release: 2021 SafeTREC Traffic Safety Fact Sheets

September 30, 2021
2021 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 2021 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. Historically, road safety efforts focused on changing human behaviors to prevent crashes. The Safe System approach reframes...

2021 SafeTREC Traffic Safety Fact Sheet: Speeding-Related Crashes

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper

A speeding-related crash is defined as one where a driver is speeding, racing, driving too fast for the conditions, or driving in excess of the posted speed limit. In the United States, in 2019, over one in four (26.3 percent) fatalities involved speeding, a proportion that has remained steady since 2017 following a decline in the prior decade. Speeding reduces a driver’s ability to steer safely around curves or objects, reduces the amount of time a driver has to react to a dangerous situation, and extends safe stopping distances.

Historically, road safety efforts focused on...

2021 SafeTREC Traffic Safety Fact Sheet: Occupant Protection

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper

Restraint devices such as seat belts are a key element of motor vehicle occupant protection systems. Each year, NHTSA conducts the National Occupant Protection Use Survey (NOPUS) that measures, among many variables, the use of seat belts by occupants age eight and older. The 2019 NOPUS reported that seat belt use was 90.7 percent among front-seat passengers, a slight increase from the 89.6 percent observed in 2018. Additionally, the 2019 survey found that seat belt use increased during both weekday rush hours and non rush hours. Use during weekday rush hours increased from 89.3 percent in...

2021 SafeTREC Traffic Safety Fact Sheet: Emergency Medical Services

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper

There are typically many contributing factors in motor vehicle crashes. Emergency Medical Services (EMS) play a critical role post-crash to reduce fatalities and serious injuries. Recent studies show that an effective emergency trauma care system can improve survival from serious injuries by as much as 25 percent and county-level coordinated systems of trauma care can reduce crash fatalities rates as much as 50 percent.

The Haddon Matrix (see Figure 1) applies basic principles of public health to motor vehicle-related injuries. The matrix looks at the factors in the pre-crash, crash...

NEW! SWITRS Statewide Summary Tool on TIMS

September 20, 2021

UC Berkeley SafeTREC’s Transportation Injury Mapping System (TIMS) has been developed to provide quick, easy and free access to California crash data from the Statewide Integrated Traffic Records System (SWITRS) that has been geo-coded to make it easy for users to query, map, and download collision data.

As part of an ongoing effort to support local and state agencies efforts to improve traffic safety, a new tool is now available, the...

New Research Highlight: Selected Research on Road Diets

May 5, 2021
Research highlights how road diets have been shown to reduce traffic injury

SafeTREC's graduate student researcher Elijah Wade and research analyst Bor-Wen Tsai have co-authored a new research highlight, "Selected Research on Road Diets."

Abstract Pedestrian and bicyclist injury and mortality is a common occurrence in California. Data from the Transportation Injury Mapping System found that serious injuries among bicyclists and pedestrians increased between 2017-2019, with 3,174 recorded in 2017 and a peak of 3,495 serious injuries in 2019. Along with serious injuries, there has also...

New Research Highlight: Commercial vehicles, fatigue, parking, and safety

August 30, 2020

UC Berkeley SafeTREC is excited to share a new research highlight by research analyst Katherine Gosselin, "Commercial vehicles, fatigue, parking, and safety."

New research highlight focuses on the public health and road safety hazards of commercial driver operator fatigue and not having access to truck parking

For commercial drivers, operator fatigue and parking in undesignated areas can result in dangerous collisions. Exacerbating this issue is a lack of freight truck parking, making it difficult for truck operators to find a safe spot when in need of rest. For bicyclists and...