Hazard Perception, Space Management, and Speed Control
What this domain covers
Hazard perception, space management, and speed control test whether you scan ahead, keep a cushion, and choose a safe speed for a heavy combination. Stopping distance and brake fade are central because a loaded rig cannot stop like a car.
Core rules
- Scan 12–15 seconds ahead and check mirrors regularly. Look for brake lights, lane changes, work zones, and shoulder activity.
- Following distance: below 40 mph, allow one second per 10 feet of vehicle length; above 40 mph, add one second. A 60-foot combination at 55 mph needs about 7 seconds.
- On downgrades, select a lower gear before the descent and use engine braking. Do not ride the brakes; brake fade can leave you without stopping power.
- Adjust speed for rain, ice, fog, curves, and heavy traffic. Use escape ramps if brakes fail; do not coast in neutral.
- At railroad crossings, slow down, look both ways, and ensure the trailer clears the tracks before crossing.
Worked example
A 60-foot combination at 55 mph: 6 seconds for length plus 1 second for speed equals 7 seconds. At 55 mph (about 81 ft/s), that is roughly 565 feet-over a tenth of a mile. In rain, increase it further.
Traps that cost marks
Tailgating; relying on brakes instead of gears on a downgrade; looking only at the vehicle ahead; crossing tracks without room for the trailer; and treating the posted speed limit as a safe speed in bad weather.