Turns and Lane Control with Long Vehicles
Turns and Lane Control with Long Vehicles
This domain tests where a long combination should be positioned for turns, how much room the trailer needs, and how to use mirrors and signals. The exam focuses on right-turn setup, left-turn clearance, lane discipline, and the danger of turning too soon.
Core rules
- Right turns: approach from the right lane, keep the tractor close to the curb but not against it, move forward until the trailer axle clears the corner, then turn. You may need to swing wide, but only where legal and safe.
- Left turns: approach from the left lane or the lane marked for left turns; do not cut across the right lane. Watch the trailer's rear wheels in the mirror.
- Complete the turn in the correct lane. Do not drift into a second lane.
- Signal early and cancel after the turn.
- Use both flat and convex mirrors; the trailer cuts inside.
- Slow down before the turn, not during it.
Worked example
A 60-foot combination approaches a right turn. The driver swings left before the corner, then turns right. The trailer's left-side tires cross the center line and the right-side trailer tires clip the curb. The driver turned too early and swung too wide. The better plan: stay in the right lane, pull forward until the drive axles are near the corner, swing left only enough to clear the curb, and watch the trailer tires complete the turn.
Traps
- Beginning the turn before the trailer clears.
- Swinging into an adjacent lane without checking.
- Cutting a left turn across traffic.
- Forgetting tail swing at the front of the tractor.
- Using only the flat mirrors.
Key points
- Right turn: right lane, forward first, then turn.
- Left turn: left lane, watch trailer tires.
- Complete the turn in one lane.
- Convex mirrors show the trailer's cut.
- Slow before the turn, steer smoothly.