Rain and wet roads


November 11, 2013

Yes, I know we don’t get a lot of rain in Oman! However, it’s getting near the time of year when rain and wet roads can start creating problems for us when driving. So here goes.

I mentioned in my Muscat Daily article of September 9 that when driving on wet roads, we require at least twice the distance to stop compared to a dry road.

This is because when driving in rain or when the road is wet your ability to stop will be reduced and twice the overall stopping distance will be required.

Also remember, my previous advice about modern vehicles’ ABS braking systems extending overall stopping distance, albeit providing better control.

So to compensate for this, on wet roads reduce your speed and increase the distance between you and any vehicle in front. Rain also acts to reduce visibility. Even with your windscreen wipers on, rain can obscure the view through the screen. The problem is made worse when windows begin to get misty.

To ease such problems
•Keep your windows clean.
•Use a quality windscreen-washer fluid and monitor the reservoir more regularly than normal.
•When windows start to mist, use fans appropriately.
•Replace ineffective windscreen wipers.
•Turn your lights on. As a rule, whenever we need to use our windscreen wipers, we should consider turning on dipped headlights (not sidelights).
•When overtaking in the rain, we should use our wipers on their fastest setting. This will help deal with any spray that comes from the car we overtake.

Spray forced up from the road surface by vehicle tyres causes hazards because this can very quickly cover the windscreen and reduce visibility to almost zero.

Apart from increasing our ability to stop in good time, creating an appropriate distance between our vehicle and the one in front also reduces the chance of a loss of visibility due to the spray from the one in front.

If you see a vehicle coming towards you, switch the wipers to full speed in readiness for water hitting your windscreen. As with other aspects of good driving, we should be proactive, not reactive.

In heavy or persistent rain, as the rain pools on the surface of the road, ‘aquaplaning’ can become a serious risk. Aquaplaning (sometimes called ‘hydroplaning’) is when the tyres surf the pooled water because the tread can’t dissipate the water quickly enough.

This results in a loss of traction between tyres and road and is like driving on ice. Aquaplaning will happen more readily if our tyres are badly worn (see my Muscat Daily article of September 16.)

We can tell when we’re aquaplaning because the steering becomes abnormally light. The way out of an aquaplane is to gently release the accelerator.

This slows the vehicle gradually and allows the tyres to regain traction. If practicable, avoid braking and steering because control can suddenly be lost if traction returns while we’re steering in the wrong direction. Aquaplaning will not happen if speed is appropriate for the conditions.

Using cruise control on wet roads is not advisable as it can cause problems if an aquaplane occurs (available space prevents me from expanding on that here). Avoid wadis in wet weather.

Look for the level of water on the marker posts and always obey well-publicised advice. People die every year by trying to cross flooded wadis.

If the level of water is such that it’s safe to drive through, follow this advice
•Go slowly. Speeding through the water will create a wave that will rise up towards the engine and exhaust pipe.
•Keep the engine running above idle to reduce the chance of water entering the exhaust pipe and stalling the engine.
•Once clear of the water, and if safe, dry the brakes by lightly applying them.

Safe driving!