The first heavy rain following a prolonged dry spell can create deceptively slippery road conditions, prompting drivers and trainers to prepare for what is sometimes described as the summer ice road risk.
During extended periods of dry weather, engine oil, rubber particles, dust and other debris gradually accumulate on the road. When rain eventually arrives, the water mixes with these deposits to create a greasy surface layer that can substantially reduce tyre grip.
For learners who have spent much of the summer driving in dry conditions, the change can be particularly significant. Familiar roads may suddenly require gentler steering, earlier braking and considerably greater separation from other vehicles.
Why roads can become more slippery
Hot weather can affect the road itself. High temperatures may soften the bitumen within the surface and bring it upwards, smoothing the texture and reducing skid resistance.
Rainwater can then combine with the material already present on the road. The resulting conditions may be most hazardous during the early stages of rainfall, before sufficient water has washed the accumulated contamination away.
Standing water creates a further risk. If a tyre cannot disperse the water beneath it effectively, it may lose contact with the road and begin to aquaplane. At that point, the driver’s ability to steer, accelerate or brake can be severely reduced.
An important teaching opportunity
The return of wetter weather gives driver and rider trainers an opportunity to revisit how their pupils adapt to changing conditions.
Steve Ramsey, Motoring Expert at Go.Compare, said stopping distances can double on wet roads and encouraged drivers to spend time checking their vehicles and refreshing their wet-weather driving habits.
Training should reinforce the importance of:
- Leaving at least a four-second gap from the vehicle ahead
- Reducing speed before reaching standing water
- Braking, steering and accelerating smoothly
- Looking well ahead for spray, surface water and changes in road texture
- Keeping windows, mirrors, lights and number plates clean
- Checking that tyres and windscreen wipers remain effective
Although the legal minimum tyre tread depth for cars is 1.6mm across the central three-quarters of the tyre, legal compliance alone does not guarantee optimum wet-weather performance. Drivers should regularly inspect their tyres for tread depth, pressure, damage and uneven wear.
Trainers can also help pupils recognise that conditions may change faster than their habits. A driver who has become accustomed to summer grip levels must consciously allow more time and space when rain returns.
The advice was provided by Go.Compare as part of its guidance for drivers preparing for wetter autumn conditions.
