What are the four factors affecting the distance a commercial vehicle needs to stop?

The distance a commercial vehicle needs to stop is influenced by several critical factors, one of which is brake condition. Well-maintained brakes ensure that a vehicle can stop efficiently, reducing stopping distances significantly. Traction is another vital factor; it refers to the grip between the tires and the surface of the road, which can vary with conditions (wet, icy, gravel, etc.), impacting how quickly a vehicle can come to a halt. Speed plays a crucial role as well; the higher the speed, the longer the stopping distance required due to the increased momentum that must be overcome in order to stop.

Weight is also determinative, as heavier vehicles require more distance to stop due to greater momentum. As weight increases, the energy that must be dissipated during braking also increases, thereby extending the stopping distance.

The other factors included in different options, such as visibility, weather, traffic, and acceleration, while relevant in certain driving scenarios, do not directly pertain to the physical dynamics impacting stopping distances in the same way that brake condition, traction, weight, and speed do. These four primary factors create a comprehensive understanding of how to assess and ensure safe stopping distances for commercial vehicles.