Wet national road, gravel lorry, brake fade and a ferry
Dimitris is driving his 2011 diesel estate on a two-way national road outside a built-up area, where the limit is 90 km/h. It has been raining for an hour. He is following a lorry loaded with gravel at a gap of about one and a half seconds, and the lorry's spray makes it hard to see even its rear lights. The estate carries four adults, a full boot and a loaded roof rack; the rear tyres are at 2.0 bar instead of the 2.4 bar recommended for a full load. The road descends for 3 km towards a junction, and after two minutes of continuous braking he notices the pedal feels long and the car pulls slightly to the right. He is due at a ferry in 20 minutes and the next sailing is six hours later.
1. Assess his following distance and speed. What gap is appropriate, and why is the standard rule not enough here?
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One and a half seconds is far too close; he is effectively driving blind. The standard minimum is the two-second rule in dry conditions. In rain, on a wet road, that must be at least doubled to four seconds, and behind a spraying lorry several more seconds are needed because:
- He cannot see the road ahead. The lorry blocks his view of the surface, the junction and any hazard beyond it; his only information is the lorry's rear lights.
- Stopping distances grow. At 90 km/h on a wet road, a loaded estate needs roughly 80–100 m to stop, against perhaps 55–65 m dry. At 1.5 s the gap is about 37 m - the car would be inside the lorry before the driver had finished reacting.
- The lorry's own stopping distance is longer, and gravel loads shed stones and spill onto the road.
- Load and pressures. Four adults, a full boot and a roof rack add maybe 10–20% to stopping distance; rear tyres at 2.0 bar instead of 2.4 bar are underinflated, which reduces grip, raises tyre temperature and makes the rear less stable.
The 90 km/h limit is a maximum for ideal conditions, not a target. His correct speed is whatever lets him stop within the distance he can see to be clear - probably 60–70 km/h, and less behind the spray.
2. The pedal has gone long and the car pulls right. What is happening and what should he do, in order?
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This is brake fade from overheating. Continuous braking on a 3 km descent converts kinetic energy into heat faster than the discs and fluid can shed it. The fluid can boil, producing gas bubbles that compress instead of transmitting force - hence the long pedal. The pull to the right suggests one side is hotter or a caliper is binding.
Immediate sequence:
- Stop using the brakes as the primary control. Select a lower gear - third or second - and let engine braking hold the speed. In an automatic, move to a low manual range.
- Release the pedal so the brakes can cool in the airflow, braking in short firm applications rather than riding them.
- Find a safe place to stop - a lay-by or wide verge - and let the brakes cool. Do not pour water on hot discs.
- If the pedal goes to the floor, use engine braking, the handbrake gently and progressively, and the verge if necessary. Do not coast in neutral, ever.
- Do not continue until the cause is checked; a long pedal on a loaded car with children aboard is a defect, not an inconvenience.
The correct descent technique is: low gear before the descent, brakes used briefly and firmly, speed controlled by the engine.
3. How should the ferry deadline change his decisions - and what would you say to him directly?
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It should change nothing about the driving; it is a reason to be more disciplined, not less. Time pressure is one of the most reliable predictors of crash involvement: it narrows attention, encourages close following, late braking and risky overtaking, and makes a driver treat a limit as a target.
The honest trade-off is simple: a missed ferry costs money and half a day. A crash on a wet descent with a loaded car costs far more - and the six-hour wait is the good outcome. The decision that should have been made was to leave earlier or take the later crossing, not to make up time on a wet road.
What I would say to him:
- "You are already late; the only thing you control now is how you arrive."
- "Drop back to four-plus seconds, drop your speed to what you can see, and let the ferry go."
- "Deal with the brakes before the next descent - that pedal is telling you something."
The professional driver's habit is to build the delay into the plan and to treat every deadline as subordinate to the stopping distance available.