Kansas driving lesson · Visual Search, Speed & Space Management
Stopping distances
A 3-minute lesson from the Kansas course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
Stopping takes longer than most drivers think. Before the brakes even work, you travel while you notice the hazard and while your foot moves. Speed makes everything worse: braking distance and crash force grow much faster than speed does.
Perception distance
How far you travel, in ideal conditions, from when your eyes see a hazard until your brain recognizes it. Mental and physical conditions and visibility affect it.
Look at least ten seconds ahead to avoid panic stops. Sudden stops usually mean you weren't watching traffic or were following too closely, and they make it hard for drivers behind you to stop.
You're going 40 mph instead of 20 mph through a neighborhood. Doubling your speed makes both your braking distance and the force of any crash 4 times greater, not twice.
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.
What is the average perception time for an alert driver?
¾ second to 1 second
1 to 2 seconds
Less than one quarter of a second
3 to 4 seconds
Answer: ¾ second to 1 second
Perception time — from seeing a hazard to recognizing it — averages ¾ to 1 second for an alert driver.