ABS, tyre pressure and a wet braking emergency
You drive a 2019 front-wheel-drive hatchback with ABS, ESC and tyre-pressure monitoring. The dashboard shows a yellow tyre-pressure warning that came on 20 km ago; you have not checked the pressures. It is 6 °C, the road is wet with standing water in the wheel ruts, and you are on a rural road at 90 km/h in a 100 km/h zone. A deer steps out about 60 m ahead. You brake hard. The car pulls slightly to the right and the pedal pulses under your foot. Behind you a van is following at roughly 20 m.
1. Explain what the pulsing pedal and the slight right pull mean, and how you should brake and steer in this situation.
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The pulsing pedal is ABS working: it is releasing and reapplying brake pressure at each wheel to stop a wheel locking, so I keep firm, continuous pressure and do not pump the pedal or release it. The slight pull to the right, together with the tyre-pressure warning, suggests uneven tyre condition - most likely a soft or under-inflated tyre on one side, or different grip left to right - so the car is not braking straight. I hold the wheel firmly and steer where I want to go; with ABS I can brake and steer at the same time. I aim to pass behind the deer rather than swerve into oncoming traffic. At 90 km/h on a wet road, 60 m is very little: wet grip roughly doubles the dry stopping distance, and standing water in the ruts can cause aquaplaning, where the tyres lose contact and neither braking nor steering works. I brake hard and early, keep the car straight, and accept that an impact may be unavoidable; a controlled straight-line stop is safer than a violent swerve.
2. What do you do about the tyre-pressure warning and the van behind after the incident?
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After stopping safely, I check all four tyres with a gauge and look for damage, because a warning that persists for 20 km can mean a slow puncture or a valve problem, not just cold-weather pressure loss. Pressures are set to the manufacturer's figures for the load; cold weather lowers pressure, so I top up and reset the monitoring system. A soft tyre on one side explains the pull and also lengthens stopping distance, so I do not continue at speed until it is corrected. As for the van at 20 m: at 90 km/h that is far too close - the recommended minimum is the 'two-second rule', which at 90 km/h is about 50 m, and more in rain. I do not brake sharply to punish the driver. I increase my own gap ahead so I can brake gently, and if the van keeps tailgating I pull over at the next safe place and let it pass.