Driving Combination Vehicles Safely: Turns, Braking, Speed, Space
Off-tracking and turns
The rear wheels of a tractor-trailer follow a shorter path than the front wheels, so the trailer cuts the corner. On a right turn the trailer's rear wheels can climb the curb or strike a pedestrian; set up wide enough that they clear, and watch them in the mirrors. Over-swinging is its own hazard - it invites traffic into the gap on your left. In multi-trailer rigs the last trailer swings widest (rearward amplification), so steering inputs must stay smooth and small.
Speed, space, braking
Following distance: one second for every 10 feet of vehicle length below 40 mph, plus one extra second above 40 mph. Slow to the advisory speed before a curve, not in it - a combination rolls over at a lower lateral force than a car. Braking distance grows with weight, and a bobtail tractor stops shorter but locks its light drive axles easily on wet pavement. On a downgrade, pick a low gear before the crest and use engine braking; overheated brakes fade.
Worked example
A 60-foot rig at 55 mph: 60 ÷ 10 = 6 seconds, plus 1 second because you are over 40 mph, equals 7 seconds. At 55 mph that is roughly 565 feet. Pick a sign or pole the car ahead passes and count "one-thousand-one" until you reach it.
Traps
Driving the car speed limit through curves; braking hard mid-curve; over-swinging a turn; checking mirrors only after the trailer has already cut the corner; using a posted truck speed as if it covered every load and grade.