What affects annual changes in traffic safety? A macroscopic perspective in Virginia
1Virginia Center for Transportation Innovation and Research, Virginia Department of Transportation, Charlottesville, VA, USA.
Journal of Safety Research
|May 3, 2015
Summary
Economic factors significantly impact traffic safety in Virginia. Changes in the Consumer Price Index (CPI) and unemployment rate correlate with reductions in traffic crashes and fatalities.
Area of Science:
- Traffic Safety Research
- Transportation Economics
- Public Health
Background:
- Virginia experienced a notable 20% decrease in traffic fatalities in 2008.
- This reduction was the largest since 1950, prompting investigation into its causes.
Purpose of the Study:
- To identify factors influencing traffic safety in Virginia from a macroscopic viewpoint.
- To understand the drivers behind the significant 2008 traffic safety improvement.
Main Methods:
- Analysis of historical Virginia traffic data.
- Correlation of 18 potential factors with seven traffic safety measures.
Main Results:
- Typical crash exposures showed weak associations with traffic safety measures.
- Economic indicators, specifically the unemployment rate and U.S. Consumer Price Index (CPI), demonstrated strong associations.
Conclusions:
- Annual changes in CPI and unemployment rate explain approximately half of the variations in total and fatal crash counts.
- A 1-point CPI increase correlates with ~2,500 fewer crashes; a 1% unemployment increase correlates with ~40 fewer fatal crashes annually.
