Motorized Vehicle Safety

2022 SafeTREC Traffic Safety Fact Sheet: Speed-Related Crashes

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper
2022
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 2020, over one in four (29.0 percent) fatalities involved speeding, a rate that increased after plateauing in the late 2010s, following a decline earlier in the 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. Analyses presented in the police traffic services...

2022 SafeTREC Traffic Safety Fact Sheet: Occupant Protection

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper
2022
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 daytime use of seat belts by occupants age eight and older. The 2020 NOPUS reported that seat belt use was 90.3 percent among front-seat passengers, a slight decrease from the 90.7 percent observed in 2018. This change, along with the changes in subsets such as time of day or day of the week, was not statistically significant.

The United States Department of...

2022 SafeTREC Traffic Safety Fact Sheet: Distracted Driving

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper
2022
The National Highway Traffic Safety Administration (NHTSA) defines distracted driving as activities that divert attention away from safe driving. This may include talking on the phone, texting, eating or drinking, manipulating audio systems, etc. According to the National Safety Council, cell phones remain a top distraction because of the length of time they are used by drivers on a daily basis.

The United States Department of Transportation uses the Safe System Approach to work towards zero roadway fatalities and serious injuries. The Safe System Approach recognizes that people...

2022 SafeTREC Traffic Safety Fact Sheet: Alcohol-Impaired Driving

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper
2022
While alcohol-impaired driving fatalities have fallen significantly in the last three decades, NHTSA reports that alcohol-impaired driving still comprises a large percentage of traffic injuries and fatalities. On average in 2020, someone died from an alcohol-impaired driving crash every 45 minutes. There was an increase in the number of alcohol-impaired driving fatalities and rate per 100 million Vehicle Miles Traveled (VMT) in the United States between 2019 and 2020.

The United States Department of Transportation uses the Safe System Approach to work towards zero roadway...

2022 SafeTREC Traffic Safety Fact Sheet: Aging Road Users

Katherine L. Chen
Bor-Wen Tsai
Garrett Fortin
Jill F. Cooper
2022
The older adult population in the United States aged 65 and older is expected to almost double between 2016 and 2060, from 49 million to 95 million. In 2020, there were 6,549 people aged 65 and older killed in traffic crashes in the United States; this accounted for 16.9 percent of all traffic fatalities. Older drivers 65 and older involved in fatal crashes decreased by 9.8 percent between 2019 and 2020.

As drivers age, physical and mental changes including reduced visual acuity, increased fragility, restricted movement, and cognitive impairment may directly and indirectly result in...

New Publication - Highway Crashes in California During the COVID-19 Pandemic: Insights and Considerations

August 8, 2022
Submitted by Lisa Peterson
New publication provides insights on the impact of COVID-19 pandemic on road safety in California

SafeTREC Co-Director Offer Grembek, former Postdoctoral Researcher Praveen Vayalamkuzhi, and Applications Program Manager SangHyouk Oum have co-authored a book chapter, "Highway Crashes in California During the COVID-19 Pandemic: Insights and Considerations" as part of the new publication "Pandemic in the Metropolis:...

New Publication: Learning the representation of surrogate safety measures to identify traffic conflict

June 14, 2022
Submitted by Lisa Peterson
New paper highlights a framework to identify traffic conflicts

Former SafeTREC Graduate Student Researcher and current Applied Scientist at Amazon Jiajian Lu has co-authored a new publication, "Learning the representation of surrogate safety measures to identify traffic conflict" with SafeTREC Co-Director Offer Grembek and Civil & Environmental Engineering Professor Mark Hansen in the journal Accident Analysis & Prevention.

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Learning the representation of surrogate safety measures to identify traffic conflict

Jiajian Lu
Offer Grembek
Mark Hansen
2022

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
Submitted by Lisa Peterson

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
Submitted by Lisa Peterson
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...