The truth about cruise control and aquaplaning


“Two vehicles aquaplaning” by Bidgee – Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons –

We were recently asked on Facebook about this chain email below, which has been around for a few years, suggesting that cruise control causes aquaplaning.

“A 36-year-old female was travelling between Wollongong and Sydney. It was raining, though not excessively, when her car suddenly began to hydroplane and literally flew through the air. When she explained to the policeman what had happened, he told her something that every driver should know – NEVER DRIVE IN THE RAIN WITH YOUR CRUISE CONTROL ON. The policeman told her that if the cruise control is on and your car begins to hydroplane – when your tyres lose contact with the pavement, your car will accelerate to a higher rate of speed and you take off like an airplane. She told the policeman that was exactly what had occurred. The policeman estimated her car was actually travelling through the air at 10 to 15km/h faster than the speed set on the cruise control. The policeman said this warning should be listed, on the driver’s seat sun-visor – NEVER USE THE CRUISE CONTROL WHEN THE PAVEMENT IS WET OR ICY.”

While the final phrase in capital letters is good advice, the reasons given for arriving at this conclusion are misleading. Cruise control should not be used in wet conditions but there is no reasonable explanation why it would cause aquaplaning.

What is aquaplaning or hydroplaning?

Driving in wet conditions can be more hazardous than normal dry conditions as the wet conditions affect the tyre’s ability to grip the road surface. In order to maximise the grip available to the tyres, water is dispersed via the tyre’s grooves. At higher speed, the tyre (particularly if worn) may fail to disperse the water, allowing the tyre to ride on a plane of water and lose contact with the road surface. This is commonly referred to as aquaplaning or hydroplaning.

Worn tires will aquaplane more easily for lack of tread depth. Tyres worn below their tread depth indicators are no longer capable of clearing the road of water. If you want to get your Tyres checked, book in to one of our friendly MotorServes or one of our More4Members partners, Beaurepairs or Tyreright.

How does cruise control operate?

Cruise control is a device used to keep the speed of the vehicle constant.

The speed of the wheels is constantly being measured and fed into a cruise control system that regulates the engine’s output. Under a condition where the driving wheels have broken traction, such as an aquaplane situation, the sensor would measure an increase in wheel speed. The cruise control system would then reduce the amount of throttle and maintain the set speed. (This is the complete opposite to what is claimed in the e-mail to have occurred and causing the accident.)

In addition, cruise control systems are deactivated upon application of the brake pedal, which is usually deployed in emergency situations. Hence cruise control causing a 15 km/h increase in vehicle speed, under these conditions, is not possible.

Safe use of a Cruise control

The safest way to operate a vehicle is to ensure that under all driving conditions you can control the vehicle (brake, corner and accelerate) in a safe manner. As the “cruise” control title infers, it is a device that should be used under steady driving situations.

Cruise control when deployed will attempt to keep the car at a constant speed set by the driver. Hence if it has been set to 100 km/h speed, the car will enter a corner at 100 km/h. If this is an inappropriate speed for the corner, the subsequent braking to reduce speed will affect the balance of the vehicle which may in turn induce instability in the vehicle. This will affect the vehicle handling and if not correctly compensated for by the driver, can in a worst case, result in a loss of control of the vehicle.

Wet roads significantly affect the grip of the tyres and this in turn can make corrective actions by the driver much more difficult to judge. Accordingly, the driver should assess the conditions of the road and adjust vehicle speed so it is suitable for the road.

To better understand safe operation of its cruise control, you should refer to your vehicle manual. Many owner’s manuals suggest cruise control should not be used in heavy traffic driving, city driving, and winding, undulating, slippery or unsealed roads.

Have you ever aquaplaned or do you use cruise control when you drive?

Other resources:

- Tyre Care list
Changing a tyre
- Wheel Alignment
- Tyre Pressure
 Tips for driving in the rain

Knights of the Road – The first NRMA Patrols

NRMA is celebrating 90 Years of Roadside Assistance in October. Here’s the first in a series of blogs about our story. Let us know your NRMA Memories in the comments. 


LEGENDARY SERVICE: The guides were paid a half crown commission for every new member they joined, as well as their salary of 2p.17s a week.

In 1920, a lobby group was formed called the National Roads Association (NRA) to petition for better roads. Following the success of the group and increased interest in motoring, National Roads and Motorists Association roadside assistance was born.

Smiling-guidess36_329_3On the 6 February 1924, two guides were appointed: Alfred (Stan) Povey and Sam (Mac) Hawe. The group quickly doubled and the NRMA guides, as they were called at the time, were issued with Douglas motorcycles. As the face of the NRMA the guides gained the trust of motorists, quickly seeing they were the knights of the road.

Working out of 117 Pitt Street, these guides performed a number of tasks for the multiplying motorists on the road. As well as providing mechanical first aid to stranded vehicles, the guides would move Member’s cars from park to park so as not to get a parking fine and join up new members.

One particular guide was so good at convincing motorists of the advantages of being a Member, while helping a stranded motorist, he would raise his voice putting on a theatrical display explaining his knowledge and the steps taken to revive the vehicle showing how advantageous a NRMA Membership is. The guides were paid a half crown commission for every new member they joined, as well as their salary of 2p.17s a week.

‘In those days we used to stand at the ferry wharves and sign up Members, if they needed it, we used to fix up Members’ cars. We’d change a wheel, work on the engine, even shift the car from one spot to another before the Police booked them for over parking’. Stan – In-Roads: NRMA staff journal FEB/MAR 1984

The uniform of the NRMA guides was based on the Light Horse Brigade, WWI uniform. Most likely surplus items, they wore brown jodhpur pants, serge coat, shirt, tie and boots. A leather cap was worn at all times featuring an NRMA badge on the crown and identifying number badges were worn on the collar. A long leather coat was issued for working in poor weather.

“N.R.M.A. official uniformed guides are new on duty in Castlereagh-street, from Hotel Australia to Hunter-street, between the hours of 6 and 11 p.m. These guides will extend the usual N.R.M.A. service to cars left in this locality, and will render mechanical first aid if necessary free of charge.” Sunday Times (Sydney, NSW: 1895-1930), Sunday 29 June 1924

Increase in Memberships meant increase of members in need and the guide contingent was growing. In 1927, the metro road service was divided into 5 divisions, just as the road services are divided into today, each division was looked after by a Sergeant guide. By 1929 the number of guides had increased to 50.

Neville Quist – the beltless wonder!

In 1927, many Members wrote to the Open Road praising NRMA guide Neville Quist, who helped quite a few stranded motorists in his days.

The big-ended bearing on the motorist’s model T had failed. Neville took the leather belt out of his pants and fashioned a bearing which worked well enough to get the car going and the member home.

Neville spent the rest of the day holding his trousers up with one hand while he worked with the other.

Bill Thornton: The Frying Pan Patrol Man

Bill Thornton, who worked around Bathurst in the late 1920s, once had problems of his own when the clutch plate of his motor bike gave up the ghost.

He took out his camping gear and cut the bottom out of his metal frying pan to make an emergency clutch plate.” Did I wake you? Association of Country Service Centres, 1996.

Next up - NRMA in the 30s: The Harbour Bridge and 24/7 roadside!

Share your story of how the NRMA has helped you over the years for your chance to win.

Can you help fix Sydney’s growing gridlock problem?

Traffic congestion

PREMIER’S OFFICE: “We need to think more innovatively about how our existing metropolitan-wide infrastructure could work more efficiently. “

While you’re sitting in traffic on your way home from work today, maybe use the time to think up a plan on how to reduce the gridlock that grips Sydney for much of the day.

That’s what the NSW Government is calling for with the launch of the Premier’s Innovation Initiative - effectively crowdsourcing ideas from the community and public sectors.

While the government may not (yet) be taking suggestions from the general public, interest and community groups will be invited to offer ideas of beating congestion hot spots around the city that are turning our roads into carparks at some times of the day.

The Government wants to broaden the pool from where ideas come as it battles this increasing problem.

If you have a particular road or route that makes your blood boil day after day and you think you might just have a solution, why not jump on to our interactive advocacy platform Speak Out and let us know what it is or #RedFlag it in our Seeing Red on Roads map.

Chinese cops dish out amazing punishment for high beam offenders

Police in a Chinese city are reportedly making drivers who use their lights incorrectly stare into them for five minutes (source: SMH)

Police in a Chinese city are reportedly making drivers who use their lights incorrectly stare into them for five minutes (source: SMH)

The misuse of headlights – and fog lights – have featured fairly regularly in the campaign suggestions we’ve received through our interactive advocacy platform Speak Out, but nobody has yet suggested the bizarre method of punishment reportedly dished out by one city’s traffic police in China.

The Sydney Morning Herald reports that police in Shenzhen, a major city in the country’s south, are making those who abuse the use of their headlights sit in front of a police van and stare in its lights for five minutes.

The police department posted the above picture to China’s version of Twitter – Weibo – on their official account, which has more than 650,000 followers.

“From now on, traffic police will make those found carelessly using bright lights to look at them for five minutes,” the message attached to the image said, according to a translation by the SMH.

This method doesn’t sound particularly healthy for one’s eyes so it’s not likely something that will be adopted in Australia any time soon.

A number of Speak Out suggestions have called on drivers to stop using fog lights while on the road.

“It seems to me now every car fitted with these lights is using them every night. They are not good for oncoming drivers, causing (temporary) blinding,” one user wrote.

“Please have a bit more consideration for your fellow road users and switch them off.”

Another member suggested a campaign to educate drivers how to turn their fog lights off.

“I would like to see a campaign educating drivers of late model vehicles on how and when to turn off fog lights,” they wrote.

Living in rural NSW I see more and more vehicles travelling with fog lights on when it’s not appropriate.

“As they are mounted low on the car they shine straight into the eyes of oncoming drivers.”

In NSW you are only permitted to use fog lights ‘if driving in fog, mist or other atmospheric condition that restricts visibility’.

It is also an offence to use your high beams when you are less than 200m from a car in front, or less than 200m from an oncoming vehicle.

Both of these attract a $104 fine and loss of two points.

What do you think would make a more suitable punishment for drivers who use high beams and fog lights when they shouldn’t?

To leave a note or not to leave a note?

DECENT PROPOSAL: Sorry note written by Ben Affleck in 2012, image from Daily Mail UK.

DECENT PROPOSAL: Sorry note written by Ben Affleck in 2012, image from Daily Mail UK.

Recently, I witnessed a truck knock the drivers’ side mirror off a parked car. I always wondered how this happened but had never witnessed it before. It was quite dramatic – the mirror flying across the road and glass everywhere.

I’m a fan of the honesty policy and would have been fuming if this had happened to me, so when I realised this truck wasn’t going to stop and leave a note, I took matters into my own hands.

When stopped at the lights, I managed to take down the truck’s registration. Later, when off the road, I contacted a local pub 100 metres from the scene of the accident and asked them to leave a note on the car. They did, I had a call from the police later that afternoon and phone calls from the owner of the vehicle thanking me for taking the time.

I have been told a few times over the last week how nice it was to do this and the owner of the car has been incredibly grateful, which makes me wonder how many people wouldn’t leave a note when hitting a parked car and how many would ignore it if they witnessed an incident.

And so, I did a little research. Back in 2011, NRMA Insurance conducted a survey of 450 NSW drivers and found that a note was left in less than 9 per cent of accidents. 9 per cent!

I’ve previously come back to my parked car and found a window smashed (benefits of living close to several pubs!), family members have come back to their cars with much worse damage including one hit and run that left the car undriveable and when asking around the office, it seems it’s a pretty common offence. In no cases was a note left.

I think it’s time to bring a bit of decency back to our roads.

Would you leave a note if you hit a parked car? And would you leave a note if you witnessed an incident? Share your stories in the comments below!