Tuesday 14 August 2018

Drivers beware: don't let cruise control take you to the dark side

Should we be using it at all in this country? Probably not that often, our RSA expert warns

Cruise control - stock photo
Cruise control - stock photo

A couple of weeks ago I wrote about the dangers drivers face from a sudden downpour of hailstones. I compared it to a truck spilling a load of ball bearings onto the road and the obvious effect that would have on your ability to stop a vehicle.

Another side effect I didn't mention is the danger of using cruise control in these and other situations.

'Cruise control' has quite a nice ring to it, conjuring all sorts of stylish imagery from exotic getaways to cruising down an endless highway in the Nevada desert. But the reality is far less exciting.

In fact, you could argue that when it comes to Irish driving conditions it's more a case of 'curse control' than cruise control.

Drivers generally turn it on when faced with a long, reasonably straight stretch of road - in Irish terms, a motorway. It can help to control a heavy foot and keep you within the speed limit.

While it can bring real safety benefits if used in the right conditions, it also has a dark side.

As a general rule, drivers on cruise control are less attentive and therefore slower to react to hazards when they occur.

If you have cruise control fitted on your car and you've read your owner's manual, you would know that you should avoid using the facility on slippery roads.

'But sure Irish roads are always slippery,' I hear you say. Exactly. So should we be using cruise control at all in this country? The answer is probably not that often. Here comes the technical bit. When you turn on the cruise control option on your car it basically holds down the accelerator at that speed so you don't have to keep your foot on the pedal.

However, if your car hits those hailstones I spoke of earlier or surface water, and aquaplanes, the cruise control will keep it accelerating. This can cause the vehicle to surge forward and go into a spin that even a stunt driver would have difficulty correcting.

Wet-weather driving requires constant and gentle speed adjustments by carefully controlling the accelerator, not sudden brake applications.

When cruise control is not active and your foot is on the acceleration pedal you can feel the vibration when the wheels start to slide and have more time to react.

In other words you have time to correct the problem by getting your foot off the accelerator, staying off the brake and trying not to over-steer, whereas the cruise control will keep accelerating through the problem, making it worse.

The same applies to snow, ice, hailstones and sleet. Driving in cruise mode in these conditions can be lethal.

The facility is really only for use when driving in open, mainly flat roads, in good light and under dry conditions.

It should never be used on a road that you have to slow down on for a bend, and it's best that it's not used in heavy traffic when you need to be in full control.

But what should you do if you do get into difficulty?

Unfortunately, there's no clear-cut answer. The only way of stopping cruise control is to turn it off using the button, hit the brakes or change gear. Stepping on the brakes will be most people's panic response, but this can make things much worse, particularly if the car has no anti-lock brakes.

But what about electronic stability control (ESC)? Well, for those of us who are not that familiar with safety feature terminology, this is a technology in newer cars that senses a skid or spin and disengages cruise control automatically. While this is a fantastic feature, snow or ice can interfere with sensors, and it shouldn't be used as a substitute for driver alertness. Also, not all cars have ESC fitted as standard.

You really need to read your owner's manual to understand when cruise control is safe to be used, and always heed its warnings.

Indo Motoring

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