Improper Driving and Road Rage
In most motor-vehicle crashes, factors are present relating to the driver, the vehicle, and the environment. The interaction of these factors sets up the series of events that results in a crash. It is rare (if ever) that driver error is the only factor contributing to the crash.
From 2005 to 2007, the National Highway Traffic Safety Administration’s (NHTSA) National Motor Vehicle Crash Causation Survey collected on-scene post-crash data to determine the critical reasons for the critical pre-crash event. As defined by NHTSA, the critical reason is:
“The immediate reason for the critical pre-crash event is often the last failure in the causal chain of events leading up to the crash. Although the critical reason is an important part of the description of events leading up to the crash, it is not intended to be interpreted as the cause of the crash nor as the assignment of the fault to the driver, vehicle, or environment.”
The survey concluded that the vast majority of critical reasons leading to crashes are attributable to the driver:
- Driver – 94% of critical reasons
- Vehicle – 2%
- Environment – 2%
- Unknown critical reasons – 2%
- Data Table
The number of crashes attributed to drivers is 2,046,000. Those crashes are divided into four driver error categories:
- Recognition error: Includes driver inattention, internal and external distractions, and inadequate surveillance
- Decision error: Includes driving too fast for conditions, driving too fast for the curve, false assumptions of other road user’s actions, illegal maneuvers, and misjudgment of gap or speed of other vehicles
- Performance error: Includes overcompensation and poor directional control
- Non-performance error: Most often involves the driver falling asleep
NHTSA found that 41% of crashes attributed to drivers involved recognition error, while 33% involved decision errors.
- Data Table
Source: Singh, S. (2018, March). Critical reasons for crashes investigated in the National Motor Vehicle Crash Causation Survey. (Traffic Safety Facts Crash Stats. Report No. DOT HS 812 506). Washington, DC: National Highway Traffic Safety Administration.
Police report data regarding fatal crashes collected by NHTSA is also available through the Fatality Analysis Reporting System (FARS). FARS includes crash data on driver-related factors and also indicates if speeding was a factor in a fatal crash. Up to four driver-related factors can be reported for each vehicle involved in a fatal crash.
National Safety Council (NSC) analysis of this data indicates that slightly more than half of vehicles involved in fatal crashes had no driver-related factor reported. The top reported factors include:
- Speed too fast or unsafe – 17.1%
- Failure to yield right-of-way – 7.3%
- Improper lane usage – 6.6%
- Careless driving – 6.5%
- Data Table
Aggressive, sometimes violent, behavior by drivers usually stemming from stress related to driving or non-driving factors is commonly referred to as road rage. It can involve factors like speeding, illegal maneuvers, and false assumptions of other road user’s actions.
Most road rage instances go uncounted. Only road rage instances that involve crashes are included in the crash surveillance data, totaling only 0.9% of the vehicles involved in 2019 fatal crashes. Getting yelled at, flashed an obscene gesture, and being tailgated or cut off by another driver can be very upsetting, yet never result in a crash involving injury or death. In extreme instances, road rage can spill out of the vehicle and turn into assault.
Source: NSC analysis of NHTSA FARS data.