What does 'total stopping distance' encompass?

Total stopping distance is a crucial concept in understanding how a vehicle comes to a complete stop. It encompasses the entire distance a vehicle travels while the driver perceives a hazard, reacts to it, and then actually stops the vehicle.

The correct choice includes both braking distance and reaction distance. Reaction distance is the distance traveled from the moment the driver detects a hazard to the moment the brakes are applied. This time is influenced by the driver's reaction time and the speed of the vehicle. Braking distance is the distance the vehicle travels from the time the brakes are applied until it reaches a full stop. Together, these two distances make up the total stopping distance, which is essential for safe driving and helps drivers maintain adequate space between their vehicle and others on the road.

Other options do not provide a complete understanding of total stopping distance. Some might look at components in isolation, such as only focusing on braking distance or reaction time, which does not convey the full picture of how long it actually takes to stop a vehicle. Additionally, considering only visible distance ahead does not factor in the dynamics of vehicle control and stopping distances. Thus, the correct answer aptly combines the critical aspects of both reaction and braking distances to form a comprehensive understanding of total stopping distance.