Which vehicle characteristic affects turning radius at intersections?

The characteristic that most directly affects the turning radius at intersections is the type of vehicle. Different vehicles have varying dimensions, wheelbases, and turning capabilities. For example, a passenger car has a smaller turning radius compared to a large truck or bus, which requires more space to navigate turns due to their longer wheelbases and greater overall lengths. Understanding this aspect is crucial for civil engineers when designing intersections to ensure that vehicles can maneuver safely and efficiently.

While traffic volume and driver reaction time are important factors in overall traffic flow and safety, they do not inherently change the physical ability of a vehicle to turn. Traffic volume may affect how often vehicles need to turn or the congestion experienced at an intersection, and driver reaction time influences how quickly a vehicle can respond to the intersection's conditions, but the type of vehicle fundamentally determines the geometry of its turning capability. This is why emphasizing the vehicle type is critical in the context of turning radius at intersections.