Status: Hoax
Here's an email that's been circulating around:
"A 36-year-old female had an accident several weeks ago and wrote off her vehicle. It was raining, though not excessively, when her car suddenly began to aquaplane and literally flew through the air. She was not seriously injured but very stunned at the sudden occurrence. When she explained what had happened to a highway patrolman, he told her she should never drive in the rain with cruise control activated. If your car begins to aquaplane, it will accelerate beyond the set cruise control speed when the tyres lose contact with the asphalt."
So is there any truth to this? Is it dangerous to drive in the rain with cruise control activated? Not according to Australia's RAA (Royal Automobile Association) which recently
issued an advisory about this email:
“Should the car’s tyres break traction with the road, such as in an aquaplane situation, the increase in wheel speed would be sensed and the cruise control system would then reduce the amount of throttle and maintain the set speed. Additionally, cruise control systems are deactivated as soon as the brake is applied. As braking is usually an automatic reaction in most emergency situations, the scenario of cruise control causing an increase in vehicle speed is highly unlikely.”
I actually never use cruise control, whether or not it's raining, because I have a bit of a phobia about it. I have a fear that one time I'll step on the brake, and the cruise control won't deactivate.
Comments
I use cruise control on wet roads often enough, as long as the visibility is good and the traffic's not too heavy.
I think most car spedometers (and hence the CC) get their speed indication from the transmission. You can see this by watching the indicated speed increase when stuck in snow or mud. One would think the CC would see the same thing in the scenerio above and try to reduce speed but it would all depends on the reaction time of your CC. Before that happens you could be in the ditch.
Of course, all this is much more likely to be a problem on ice but I could see it being a problem in heavy rain too.
I think the confusion comes from the fact that, should your tires lose traction with the ground while your foot is on the accelerator, your tires will start spinning faster. Your accelerator governs how much power your engine is providing to your drive train, now how fast you're going. That's why you need to press down farther when going up a hill to maintain the same speed. In fact, a cruise control might even react faster than you in easing acceleration in the event you started hydroplaning.
However, unless it was more advanced than the systems I've used, it would not stop the acceleration. It would just try to keep the tires spinning at the same rate, making it moderately more dangerous than controlling it yourself. A person would pull their foot off the accelerator first, then either brake or try to keep control until the tires reconnect. Cruise control would keep acceleration up, but your speed would drop off making it harder for your tires to reconnect with the pavement.
I have used CC in the rain, but I admit I'm taking a risk with it.
"However, unless it was more advanced than the systems I've used, it would not stop the acceleration. It would just try to keep the tires spinning at the same rate, making it moderately more dangerous than controlling it yourself. A person would pull their foot off the accelerator first, then either brake or try to keep control until the tires reconnect. Cruise control would keep acceleration up, but your speed would drop off making it harder for your tires to reconnect with the pavement."
You have made a couple of mistakes in who cruise control works. First, if the cruise control is on, the driver *does not have their foot on the accelerator*. That's the entire point of cruise control. Second, when the driver hits the brakes, the cruise control turns off. This is true of *all* cruise controls.
I'm also well aware that braking disengages CC, but a drive manually accelerating will take his foot off the accelerator slightly sooner than he could disengage cruise control by braking. It's clearly a more dangerous situation to use CC on wet roads, but it probably needs study to determine just how much more dangerous it is.
I'm sorry I didn't make myself clearer in my first posting.
When you're driving nine or more hours at a stretch, on a tight schedule, CC is not optional -- it's a necessity.
Here's the no-brainer: During adverse weather conditions, you set your speed lower. Going 70 MPH in a blizzard is going to be trouble whether you have CC engaged or not.
And thank you for being a trucker, Christopher. I can't count how many times I've driven across North Dakota with about zero-percent visibility. I just pick a Semi and follow it at a respectful distance.
Oh and Alex I had an experience with cruise control that definitely made me leary of them. I had recently purchase a used car with cruise control. When I tried to engage it nothing happened, until about 15 mins later, suddenly the car decided to accelerate. Thinking is was just coincidence I tested it again, same results. It left me not trusting cruise control.
Hydroplane, not aquaplane. Aquaplaning is kneeboarding behind a motorboat.
Posted by Marc on Thu Apr 13, 2006 at 09:14 AM
Aquaplaning is the British word for Hydroplaning.
I have been told that a late 90's BMW model has had a serious problem with the cruise control wiring and some cars have surged forward and increased accelerating until the driver shut off the key (thereby losing their power steering) or often the car crashed into something.
The drivers stated that when they pressed on the brake, it just accelerated faster and faster (due to the short). Most said that it was going 70 or 80 or 90 by the time it crashed.
Even though mechanics have proven that the wires or insulation shorted out, the BMW experts deny that the car has a flaw. BMW blames it on driver error. It seems strange that these people all have the same story and their mechanic find a problem but BMW does not. Many people have been killed, so no wonder that BMW denies any liability.
I have driven many cars with CC and had no problems except with a 1985 Firebird. In that case, the car was about 2 years old and the CC was often left engaged by my teenagers but not set. Eventually, the CC simply activated itself without the driver knowing it until the car surged ahead, without notice. I can understand about the guy who bought a used car and it sounds as if it did the same thing. After the problem with the Firebird. I told my family members to never turn the CC on again, as it was unreliable.
I am interested in purchasing a BMW but there seems to be so much "hush - hush" by BMW that I am not uncertain if the CC problem is universal or just one model and which model is in question.
Does any body know anything about this?
Thanks a million!
This is something that folks might want to look into itself -- although it's still controversial to some extent.
"Sudden acceleration" is not a hoax per se. Its spread was unintentional, and was initially believed by many, including some in the industry.
This all came to a head one evening in downtown Minneapolis, when a police van ran up onto the sidewalk during the annual "Holidazzle" parade. The van jumped the sidewalk, injuring a couple of folks and killing a child. The van continued to accelerate as it crashed into the window of a nearby store.
The police at first concluded it was a case of sudden acceleration -- I believe, in no way deceptively. They really believed it, as so many do.
The subsequent police investigation, including plenty of open debate on the subject in the media, concluded what many people already suspected: The driver of the police van hit the gas instead of the brake, and instinctively jammed on the "brake" harder when he started to accelerate.
This appears to be the cause of most, if not all, "sudden acceleration" incidents.
BMW is probably right about the user error. (Although, some models do appear more susceptible, because of the placement and size of the gas and brake pedals.)
If anyone owns a late-model BMW that they're worried might hurtle them helplessly into a tragic car wreck, I will nobly sacrifice myself by taking it off their hands for them.
"Hydroplane, not aquaplane. Aquaplaning is kneeboarding behind a motorboat."
An Aquaplane is a board for riding on water, pulled by a speedboat. However, when used as a verb it may describe either the action of riding on an aquaplane or to describe the slide of a vehicle uncontrollably on a wet surface.
The word hyrdroplane refers to a type of boat or submarine control surface, but can also be used (mainly in North America) as another term for the verb aquaplane.
Apologies for detracting from the main topic, but it really annoys me when people correct others wrongly.
The moral of this lessons is:
DON'T DO IT!!!!