ROR crashes involve vehicles that leave the travel lane and encroach onto the shoulder and beyond and hit one or more of any number of natural or artificial objects, such as bridge walls, poles, embankments, guardrails, parked vehicles, and trees. (Because trees are the most abundant objects along the road, they are treated as a separate emphasis area.) ROR crashes usually involve only a single vehicle, although an ROR vehicle hitting a parked vehicle could be considered a multivehicle crash. An ROR crash, which typically consists of a vehicle encroaching onto the right shoulder and roadside, can also occur on the median side where the highway is separated or on the opposite side when the vehicle crosses the opposing lanes of a nondivided highway.

Reducing the likelihood that a vehicle will leave the roadway through roadway design (e.g., flattening curves or installing shoulder rumble strips) prevents deaths and injuries resulting from ROR crashes. When an errant vehicle does encroach on the roadside, fatalities and injuries can be reduced if an agency either can minimize the likelihood of the vehicle crashing into an object (e.g., through object removal) or overturning (e.g., sideslope flattening) or can reduce the severity of the crash (e.g., by installing breakaway devices). ROR crashes involve vehicles that leave the travel lane and encroach onto the shoulder and beyond and hit one or more of any number of natural or artificial objects, such as bridge walls, poles, embankments, guardrails, parked vehicles, and trees. (Because trees are the most abundant objects along the road, they are treated as a separate emphasis area.) ROR crashes usually involve only a single vehicle, although an ROR vehicle hitting a parked vehicle could be considered a multivehicle crash. An ROR crash, which typically consists of a vehicle encroaching onto the right shoulder and roadside, can also occur on the median side where the highway is separated or on the opposite side when the vehicle crosses the opposing lanes of a nondivided highway.

Reducing the likelihood that a vehicle will leave the roadway through roadway design (e.g., flattening curves or installing shoulder rumble strips) prevents deaths and injuries resulting from ROR crashes. When an errant vehicle does encroach on the roadside, fatalities and injuries can be reduced if an agency either can minimize the likelihood of the vehicle crashing into an object (e.g., through object removal) or overturning (e.g., sideslope flattening) or can reduce the severity of the crash (e.g., by installing breakaway devices).

Further Reading:

A Guide for Addressing Run-Off-Road Collisions