Spring showers create hazardous roads

The weekend weather forecast promises a break in the warm, sunny conditions the UK has enjoyed for the last month. The thundery showers we’re expecting won’t just be an inconvenient end to a prolonged bout of sun worshipping: they’ll also create hazardous road situations that drivers should prepare themselves for.
 
In long spells of dryness, substantial deposits of oil, rubber and waste fuel accumulate on road surfaces. While the roads are dry, these deposits aren’t too much of a problem, but introducing moisture into mix changes the situation dramatically. Oil/fuel and water do not mix, causing a tactile film to float on the surface of the moisture, which reduces the ability of tyres to gain traction on the road. This, in turn, affects directional control and braking.
 
The first five minutes of a downpour are the most crucial, creating conditions that are different to those encountered with just standing water. The drains cannot begin to clear the oil and water mix until there is sufficient volume to reach the drains and cause a continual flow. This process is further slowed by microscopic beads of rubber from vehicle tyres, which get into the pores of the tarmac, preventing the flow of rainwater to the drains. This denser material also sits on the road until the volume of water increases to a level that is sufficient to move it.
 
While this is all unfolding, vehicle traction is greatly reduced. Motorcyclists are vulnerable to the reduced visibility through ‘dirty’ spray, manhole covers and any painted lines on the road, which become more slippery through their glass and petroleum–based recipe. For drivers, windscreens start to suffer with a milky-like residue thrown up from vehicles in front: when wipers are applied, the driver’s vision is obliterated by visual distortion for probably two sweeps of the wipers, during which time the car travels some considerable distance blind.
 
Howard Redwood, head of road safety for DIAmond Advanced Motorists, expressed the need for caution while driving in the kinds of road conditions expected over the weekend, saying: “Drivers have to adapt to the changing conditions and not simply drive to those that existed when their journey started. Driving blind is a highly dangerous and is often the cause of pile-ups. Bear in mind that road situations never change suddenly, they are always in a state of flux, so be prepared.
 
“Before going out in your car, check that your windscreen washer fluid is topped up and wiper blades are clean and in good condition; ensure that your tyres have enough tread and at the correct pressure; and always leave a stopping distance between yourself and the vehicle in front. These three simple things should help you deal with whatever the unpredictable British weather can throw at you – this weekend and all year round.”