• June 27th, 2018

Major findings:

    • Primary Contributing Circumstance: Following Too Close is by far the greatest primary contributing factor in the AD involved subset of crashes, followed by Improper Lane Change/Use, Driving too fast for Conditions, and Ran Traffic Signal. When Over Speed Limit is combined with Driving Too Fast for Conditions, these combined speed related items become second place
    • Year: Year is of interest because it shows that AD crashes are increasing at very close to their non-AD counterparts. This is expected since the AD filter covers a large proportion of crashes in general. AD has a fairly stable proportion compared to total crashes, which indicates that any changes are due to changes in overall crashes in general.
    • Distracted Driving Officer’s Opinion: Distracted driving is involved in only about 10.4% of aggressive driving crashes, as compared to 27.7% of all nonaggressive crashes. This is probably because the reporting officers in aggressive driving crashes consider other things of greater importance. Other distractions outside of the vehicle seem to be of greatest concern, and perhaps related to the presence of aggression.
    • Number Killed: Single fatality crashes were significantly under-represented, while all multiple fatality crashes were over-represented. This is highly correlated to the increased speed proportion.
    • Vehicle Type: The most over-represented AD vehicles tend to be passenger cars and motorcycles. The most under-represented are pick-ups, SUVs, trucks and mini-vans.
    • Traffic Lanes: Generally, greater the number of lanes, the greater the relative inclination toward AD.