California DMV Permit Test (Class C)Rules of the Road and Right-of-WayHard
You are driving on a freeway and notice a car several car lengths ahead of you in your lane. To maintain a safe following distance, you should use the 'three-second rule'. How should you apply this rule?
- AEstimate three car lengths between your vehicle and the car ahead at all times.
- BCount 'one-thousand-one, one-thousand-two, one-thousand-three' after the car ahead passes a fixed object, and you should pass it before finishing the count.
- CCount 'one-thousand-one, one-thousand-two, one-thousand-three' after the car ahead passes a fixed object, and you should not reach that object until after you finish the count.
- DCount three seconds from when you pass a fixed object, and the car ahead should be three seconds beyond that object.
Show answer & explanationAnswer & explanation
Correct answer: C. Count 'one-thousand-one, one-thousand-two, one-thousand-three' after the car ahead passes a fixed object, and you should not reach that object until after you finish the count.
The 'three-second rule' is applied by choosing a fixed object ahead (like a sign or overpass). When the vehicle in front passes it, you count 'one-thousand-one, one-thousand-two, one-thousand-three'. If you reach the object before finishing the count, you are following too closely.
Why the other options are wrong
- A. Estimating car lengths is less precise and reliable than the time-based three-second rule.
- B. This describes following too closely, not a safe distance.
- D. The count starts when the car ahead passes the object, not when you pass it.
Three-Second Rule
The 'three-second rule' is a method to ensure a safe following distance by counting three seconds after the vehicle ahead passes a fixed object before your vehicle reaches that same object.
- Increases in bad weather or heavy traffic.
- Provides adequate reaction time.
- A fundamental defensive driving technique.
Memory trick: Three seconds to see, three seconds to be free.