Judging Accurate Following Distance and Speed
Last reviewed: 2026 · Driviology Road Safety Education Team
Quick Answer
Use the two-second rule as a baseline for following distance, and extend it in poor conditions, so you can accurately judge whether you have enough time and space to react.
Judging distance and closing speed accurately is a learned skill, not something most new drivers are naturally good at. A simple, repeatable method removes the guesswork.
Why Accurate Judgment Matters
Misjudging the gap to the vehicle ahead, or how fast a car is approaching from a side street, is behind many close calls and rear-end collisions. A consistent method for judging distance takes the guesswork out of decisions made in seconds.
The Two-Second Rule in Practice
Pick a fixed point on the road ahead, such as a sign or line. When the vehicle in front passes it, count "one-thousand-one, one-thousand-two." If you reach that point before finishing the count, you are following too closely.
Adjusting for Conditions and Vehicle Size
Double your following distance in rain, and increase it further on snow or ice, or when following larger vehicles that block your view ahead. See our Canadian speed limits guide for how posted limits and following distance work together.