Final answer:
"Single vehicle/run off the road" refers to a car veering off the road in the context of road safety.
Step-by-step explanation:
"Single vehicle/run off the road" refers to C, a car veering off the road. In the context of road safety, this term is used to describe a situation where a vehicle leaves the travel lane and ends up off the road. This can happen due to various reasons such as driver error, distracted driving, or adverse road conditions.