The Sway on the Bridge
You are pulling an empty 53-foot van on a two-lane bridge with a crosswind gusting to 35 mph. You are traveling 60 mph. The trailer begins to sway side to side, gently at first, then with increasing amplitude. You are halfway across the bridge with no shoulder. A truck is following close behind you. Your trailer is empty, which makes it lighter and more susceptible to wind and to sway.
1. What do you do with the accelerator, brakes, and steering as the sway grows?
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Do not brake hard and do not steer against the sway.
- Ease off the accelerator smoothly and let the rig slow down gradually. Slowing reduces the energy feeding the sway.
- Hold the steering wheel firmly and keep it steady - small corrections only. Fighting each swing with big steering inputs adds energy and makes the sway worse (rearward amplification).
- Do not apply the brakes hard. Hard braking on a swaying combination can unload tires and trigger a jackknife or a trailer swing.
- If you have room and the sway is not settling, gently accelerate slightly to pull the trailer straight - but only if the road and traffic allow; on a bridge with no shoulder, steady and slow is usually safer than a power move.
- Once across, pull off at the first safe place, check the load and tires, and reduce speed for the rest of the trip.
The principle: sway is a feedback loop. Your inputs should damp it, not feed it. An empty trailer in a crosswind is the classic case - slow down before it starts.
2. The truck behind is tailgating and the sway is not settling. What are your options, and what do you not do?
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Options:
- Continue to slow gradually and hold a steady line. The tailgater is a hazard, but you cannot fix that by speeding up into a sway.
- Use your four-way flashers to signal that you are slowing and that there is a problem.
- As soon as the bridge ends and a shoulder or pull-off appears, get off the road and let the traffic pass. A swaying empty trailer is not something to 'push through' at speed.
- If the sway becomes violent, the least-bad move is a controlled, gentle reduction in speed with steady steering - not a panic stop.
Do not:
- Speed up to get away from the tailgater.
- Brake hard to force the trailer straight.
- Steer sharply to correct each swing.
The tailgater's behavior is out of your control; the sway is not. Manage the sway first, then deal with the traffic.