U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
This bar graph evaluates ADT as a risk factor for road departure crashes. For each of eight ADT ranges the graph demonstrates two series: how much of the roadway system falls within the specified ADT range (length, percent), and the amount of severe crashes that occur along roadways with the specified ADT (percent).
For the ADT range between 0 and 200, 23% of the system is represented, accounting for 11% of severe run-off-road crashes.
For the ADT range between 200 and 400, 38% of the system is represented, accounting for 27% of severe run-off-road crashes.
For the ADT range between 400 and 600, 15% of the system is represented, accounting for 17% of severe run-off-road crashes.
For the ADT range between 600 and 800, 8% of the system is represented, accounting for 17% of severe run-off-road crashes.
For the ADT range between 800 and 1,000, 6% of the system is represented, accounting for 14% of severe run-off-road crashes.
For the ADT range between 1,000 and 1,200, 2% of the system is represented, accounting for 4% of severe run-off-road crashes.
For the ADT range between 1,200 and 1,400, 2% of the system is represented, accounting for 3% of severe run-off-road crashes.
For the ADT 1,400 and greater, 5% of the system is represented, accounting for 7% of severe run-off-road crashes.
The data shows that for roadways with ADTs less than 400, severe crashes are underrepresented, with the proportion of the system in length greatly exceeding the percentage of severe crashes that occur on these roadways.
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