DKTKey points on following distance for the Australian Capital Territory learner test. Each answer is checked against the official Australian Capital Territory handbook or road rules; use the practice-question links to test yourself.
In heavy rain, how should your gap behind the vehicle ahead compare with a dry day?
Answer: Bigger, because it takes longer to stop on a wet road
Wet roads lengthen stopping distance, so you need a larger gap behind the vehicle in front.
Practice question 376 · official source
How can you use a roadside post or sign to check your following gap?
Answer: Count the seconds from when the car ahead passes it until you pass it
Pick a fixed object, note when the car ahead passes it, then count how many seconds pass before you reach it.
Practice question 377 · official source
In wet weather or at night, how should you change your following gap?
Answer: Double it, to at least 6 seconds
Wet roads and darkness lengthen stopping distance and reduce vision. The ACT handbook says to at least double the 3-second gap, to 6 or 7 seconds or more.
Practice question 378 · official source
How do you check you have a 3 second gap?
Answer: Count 3 seconds after the car ahead passes a fixed object
Pick a fixed object, count three seconds after the vehicle ahead passes it, and you should reach it after you finish counting.
Practice question 379 · official source
In good conditions, how far behind the vehicle in front should you stay?
Answer: At least 3 seconds
Keep at least a 3-second gap in good conditions, and more when conditions are poor.