A 2-minute lesson from the Kentucky course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
Total stopping distance is how far your vehicle travels, in ideal conditions, from the moment you realize you must stop until you're stopped. It has three parts, and every part grows with speed.
Total stopping distance
Perception distance + reaction distance + braking distance—from the moment you realize you must stop until the vehicle stops.
At 50 mph you spot a stalled car. Before your foot even touches the brake, you've used up to a second perceiving and up to a second reacting—and braking alone then takes about 158 feet on dry pavement. That's why you need a big gap ahead.
Check your understanding
Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.
Total stopping distance includes perception time, reaction time, and:
Signal time
Acceleration distance
Braking distance
Idle time
Answer: Braking distance
Total stopping distance combines perception time, reaction time, and braking distance.