Aquaplaning on a Wet Expressway With Worn Rear Tyres
During a 4:30 p.m. downpour on a North–South Expressway stretch with a 110 km/h limit, your fully loaded 1.5-litre car begins to feel light and vague. The steering wheel tugs slightly left and right, the engine note rises without a matching speed increase, and standing water is visible in the right lane. Your rear tyres have about 2.0 mm of tread; the fronts have 4 mm. Wipers are on maximum and visibility is roughly 80 m. You are in the right lane, 18 m behind a pickup that is spraying water, and an SUV is close behind you. Your family is asleep inside. You need to reach an exit 6 km ahead. The radio warns of flash floods, but your exit is before the reported closure.
1. What is happening, and what should you do in the first few seconds?
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The light steering, wandering front end, rising engine note without a matching speed increase, and visible standing water point to partial aquaplaning. The rear tyres at about 2.0 mm are much weaker in water than the fronts, so the rear can lose grip first.
In the first few seconds:
- ease off the accelerator smoothly;
- hold the steering wheel firmly and straight;
- do not brake hard or jerk the wheel;
- let the car slow naturally until steering feel returns;
- avoid cruise control if it is engaged.
Once control returns, signal left, check the mirror and move gradually to a lane with less standing water. Do not try to power through the water.
2. Should you continue the 6 km to the exit at highway speed, and what do the tyre and load figures change?
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No. Continuing at 110 km/h is not justified. The rear tyres are close to the legal minimum and are poor at clearing water, while the full load increases stopping distance and makes a sudden loss of grip harder to correct. The safe choice is to reduce speed substantially, keep a larger gap, and leave at the first safe exit rather than treating the planned exit as fixed.
If conditions worsen, stop only in a safe place such as a rest area or emergency lane with hazards on, not in a live lane. After the trip, replace the rear tyres and check pressures. The immediate issue is not reaching the exit quickly; it is keeping the car stable in standing water.
3. You are 18 m behind the pickup. What following gap is appropriate, and how should you handle the SUV tailgating behind you?
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18 m is far too close in heavy rain and spray, especially at expressway speed. At 80 km/h, 18 m is less than one second. In wet conditions aim for at least 4 seconds, about 90 m at 80 km/h, and more if visibility is only 80 m. The pickup's spray is also hiding hazards ahead, so the gap must cover what you cannot see.
Do not brake sharply to warn the SUV; that risks a rear-end collision. Increase the gap ahead gradually, move left when safe so faster traffic can pass, and avoid the standing water in the right lane. If the SUV remains close, keep your speed predictable and do not make sudden lane changes.