Driving in the Wet
One-fifth of our time on British roads is spent driving in the wet, but it contributes to a third of all daytime casualties and over half of all casualties at night.
When it rains, the world changes instantly and you have to change with it. Driving technique in the rain is really no different to dry running, it just requires you to dial your reflexes in to the notion that things take longer and the driver’s inputs need to be slower and gentler to allow the tyres to cope with reduced levels of grip. Put simply, you can’t throw as much force around, so the secret to being a wet-weather ace is becoming silky smooth with the controls and keeping your cool.
The one element that is most different in terms of technique is the way you apply the brakes. In the dry, you can be assertive on the pedal and use an initial stab before you squeeze to load the front tyres, plus the car can accept greater forces. This doesn’t apply in wet or low-grip conditions. You have to be more gradual with the initial application to create slower weight transfers. Throttle technique is the same as you effectively have more power to overwhelm the tyres of the driven wheels.
Locking a tyre at the start of braking in the wet can cost you as much as 70% of your stopping power, a problem that ABS is designed to handle. Nonetheless, skid prevention is always better than cure.
On the road, there’s nothing to be gained by driving on a different part of the tarmac, as you might see watching racing cars on damp tracks. The entire surface tends to be equal in terms of grip on the road, but you can feel the change from one surface to the next.
After it rains, the road remains wet and it’s the surface condition that dictates the grip level. When the rain stops, the conditions linger, especially on local roads that are sheltered from sunlight. Wooded areas continue to drip water long after the surrounding roads have dried, and a nice coating of wet leaves handles like ice.
Ignore the loonies who want to tailgate in these conditions and keep a longer distance to traffic ahead so you can see well beyond the immediate. You have a quarter less grip for stopping and accelerating, 50% less on smooth, slippery roads and half the cornering grip of dry running.
In the unlikely event that you get a long period of sun in this country, cars lay down lots of rubber on the road surface. It becomes so highly polished by oily lubricants that it becomes less porous and reflects sunlight. The first droplets of rain sit on top of this layer and create a greasy film, which just sits there, waiting to undermine you.
Look out for anything that shines, from manhole covers to cobblestones, and be especially mindful of regular stopping points such as traffic lights, off ramps, bus stops and taxi ranks. They tend to get doused with slick lubricants, so leave enough stopping distance so you can feather the brake pedal for the last few metres in the wet.