  Economic factors can have substantial effects on transportation crash trends.
This study makes a comprehensive examination of the relationship between the
retail gasoline price (including state and federal fuel taxes) and
transportation fatal crashes from 2007 to 2016 in the US. Data on motor
vehicle, bicycle and pedestrian fatal crashes come from Fatality Analysis
Reporting System (FARS) provided by the National Highway Safety Administration
(NHTSA) and the gasoline price data is from U.S. Energy Information
Administration (EIA). Random effect negative binomial regression models are
used to estimate the impact of inflation-adjusted gasoline prices on trends of
transportation fatal crashes. Initial results combined with results of previous
studies showed that gender and transportation mean type (motorcycle,
non-motorcycle, bicycle and pedestrian) play prominent roles in interpreting
the final model, so by using random effect negative binomial regression, seven
models are developed to evaluate the effects of gasoline price changes on total
population, male, female, motorcyclists, non-motorcyclists, bicyclists and
pedestrians separately. Our findings suggest that increasing the gasoline
prices will not significantly alter the number of total fatal crashes. However,
by looking at different vehicle types, it is estimated that one dollar increase
in adjusted gasoline price is associated with 24.2% increase in the number of
motorcycle fatal crashes, 1.9% decrease in the number of non-motorcycle fatal
crashes, and 0.7% decrease in the number of pedestrian fatal crashes. Also,
there is no noticeable difference between male and female in response to the
gasoline price changes.
