On-the-Road Safety: Speed, Following Distance, Lane Use, and Turns
What this domain tests
This section tests speed choice, following distance for a long vehicle, lane discipline, and turns that account for a bus's size and off-tracking.
Following distance
Use one second for each 10 feet of vehicle length at speeds below 40 mph, plus one additional second. At speeds above 40 mph, add one more second. A 40-foot bus below 40 mph needs at least 5 seconds; a 45-foot bus at 50 mph needs 4.5 plus 1, rounded up to 6 seconds.
Speed and lane use
Obey the posted limit and reduce speed for traffic, weather, curves, and passenger comfort. Stay in the right lane except to pass or turn. Do not use the left lane for continuous travel.
Turns and clearance
Turn from the proper lane, swing wide enough to keep the rear wheels off the curb, and watch off-tracking: rear wheels track inside the front wheels. Check mirrors throughout the turn. Know your height before passing under bridges or canopies.
Worked example
A 45-foot bus is traveling 50 mph on a rural highway. The minimum following distance is 45 divided by 10, which is 4.5 seconds, plus 1 second because the speed is above 40 mph, giving 5.5 seconds. Round up to 6 seconds for a practical cushion.
Traps
- Using a car's 3-second following rule in a bus.
- Turning from the wrong lane or cutting the corner into a curb.
- Forgetting that the rear wheels track inside the front wheels.
- Ignoring bridge or canopy height.