To keep you cruising smoothly, we explain when to switch off this nifty little device so you can take back control.

What is cruise control?

First, let’s clear up what cruise control is and how it works. Simply put, it’s a feature available in many vehicles which can be switched on to help the driver maintain a constant speed without having to press the accelerator.

In most vehicles, the speed is set and adjusted manually by the driver. Some newer rides are fitted with advanced cruise control systems that automatically adjust the speed so the driver can keep a safe distance from vehicles ahead, without having to physically fiddle with settings or override it by braking.

When not to use it

You might already know that stop-start city traffic, dirt roads, poor weather and wet roads aren’t ideal conditions to switch into cruise control. In fact, if you use this device all the time, and you consistently disengage cruise control by applying the brakes, you’re wearing them out much quicker, and that can be costly. This can also result in braking too late, which is dangerous.

That said, cruise control should only be used when the conditions are suitable. Here are three other situations where you might want to reconsider letting your vehicle take control.

1. When the speed limit is 60km/h or under

Cruise control has now become a standard feature on most vehicles where it was once considered quite an expensive optional extra. But when is a good time to use it?

Cruise control is most handy during longer journeys on roads with highway speed limits. It’s not so helpful (or safe) when travelling at a slower pace, particularly when you need to frequently slow down for corners or slower moving traffic.

According to RAA Technical Advisory Service Manager Andrew Clark, drivers should only use cruise control when the speed limit is above 60km/h.

“The flow of traffic is often more predictable on roads with a consistent and higher speed limit,” Mr Clark says.

Hazards like roadworks can slow things down to 40km/h and sometimes 25km/h, which defeats the purpose of activating cruise control in the first place.

“Most cruise control technology won’t actually work under 40km/h.”

That said, some premium and newer vehicles have a function called a ‘speed limiter’ where lower speed limits can be set.

“No matter how far you depress the accelerator, the car will not exceed the speed selected,” Mr Clark says.

“The speed limiter is a great feature for 50km/h to 40km/h zones, or long stretches of roadworks.”

2. When negotiating bends

Unless you have a spiffy new ride with clever technology, most vehicles are fitted with a basic cruise control setting. It usually only controls the speed limit set by the driver.

In fact, standard cruise control doesn’t detect road hazards or tell you when to brake or slow down if there’s a bend in the road. That’s the driver’s responsibility.

“Usually there’s a natural reaction to ease off the accelerator when approaching bends or corners,” Mr Clark says.

“When you’re in cruise control, you might find yourself approaching or be in the corner at a much quicker speed than you realised. In this case, human intervention is needed.”

The same rule applies when cruising downhill.

“When you’re going downhill, your speed may increase above the set limit and the cruise control system won’t apply the brakes in a lot of vehicles,” Mr Clark says.

In this instance, RAA advises to turn off cruise control in advance and negotiate bends and downhill stretches with care by always reducing your speed to the signposted limit.

3. When you’re sleepy

Driving when you’re tired is never a good idea. Using cruise control under such conditions is downright dangerous.

RAA Senior Manager of Safety and Infrastructure Charles Mountain says if you feel tired you need to stop as soon as it’s safe to do so and not continue until you feel rested.

“While cruise control makes it easier to maintain a constant speed, it also means one less thing to concentrate on, so it’s easier to daydream and disconnect from driving, which always requires concentration,” Mr Mountain says.

“Another risk is that a driver may not be able to respond as swiftly and effectively in an emergency if they’re using cruise control.”

That’s when it’s time to switch off cruise control, pull over safely and rest.

So, when can you use cruise control?

If you regularly drive on country roads or freeways where the speed limit is higher and the road and traffic conditions allow you to maintain a constant speed, you can switch on cruise control and let it do its job.

“Just remember to be alert to what’s around you, in front of you and behind you, and safely intervene when necessary,” Mr Mountain says.

What the law says

While there’s no road rule that states when you should or shouldn’t use cruise control, you can be fined $201, plus a $92 Victims of Crime Levy, for driving without proper control of your vehicle – which is a risk motorists take when driving with cruise control activated in the wrong conditions.