Wet-weather following distance and a pedestrian at a marked crossing
It has been raining for an hour on the main road through Roma. The surface is wet with standing water in the wheel tracks. You are doing 60 km/h in a 60 km/h zone, following a minibus taxi at about two seconds' gap. The taxi brakes suddenly - its brake lights come on hard - because a pedestrian has stepped onto a marked crossing about 25 metres ahead of the taxi. Your tyres are legal but the tread is worn to about 2 mm on the rear. Your vehicle has no ABS. There is a car close behind you.
1. Estimate whether you can stop in the space available, and explain the factors that make this different from a dry-road stop.
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At 60 km/h you travel about 16.7 m per second. A two-second gap is about 33 m, and the taxi is now stopping within that gap. On a wet road, braking distance rises substantially compared with dry tarmac - often by around half again or more - and worn rear tyres at ~2 mm tread disperse water poorly, so grip is worse than the tyre age suggests. Without ABS, hard braking risks lock-up and loss of steering, especially with rear grip compromised.
The honest conclusion is that you may not be able to stop in the gap you have left. That is the lesson: two seconds is a dry-road figure; in rain behind a vehicle that may brake for pedestrians, you needed more like four seconds. The correct action now is maximum safe braking (firm, progressive, not stamping) while preserving steering, and accepting that the gap was too small before the hazard appeared.
2. The car behind is close. How does that affect how hard you brake, and what is the trade-off?
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There is a real trade-off: braking gently to protect against the car behind increases your risk of hitting the pedestrian or the taxi; braking hard protects the hazard ahead but risks being hit from behind.
The correct priority is the hazard you can see and control - the pedestrian and the taxi. Brake firmly enough to stop short, because a rear-end impact at low closing speed is generally less severe than striking a pedestrian. Mitigate the rear risk by braking progressively rather than stamping (giving the driver behind a moment to react and showing brake lights early), and by not swerving into oncoming traffic to create space. After stopping, keep your foot on the brake so the car behind sees you are stationary.
3. What should you do once stopped, and what should you change on the rest of the journey?
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Once stopped: stay stopped until the pedestrian has cleared the crossing, even if the taxi moves off. Do not overtake a vehicle stopped at a crossing - it may be stopped for someone you cannot see.
For the rest of the journey: increase the gap to at least four seconds in the wet, reduce speed below the limit to match the surface, and recognise that the worn rear tyres are a fitness issue - book replacement. In standing water, avoid sudden steering inputs and ease off the accelerator rather than braking hard if you begin to aquaplane.