Your thoughts on this issue related to cruise control

[Auto Tech]

You may have seen this before as an e-mail forward. What do you think
of it?
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This is DANGEROUS....I wonder how many people know about this ~

A 36 year old female had an accident several weeks ago and totaled her
car. A resident of Kilgore, Texas, she was traveling between
Gladewater & Kilgore. It was raining, though not excessively, when her
car suddenly began to hydro-plane and literally flew through the air.
She was not seriously injured but very stunned at the sudden
occurrence!

When she explained to the highway patrolman what had happened he told
her something that every driver should know - NEVER DRIVE IN THE RAIN
WITH YOUR CRUISE CONTROL ON.

She thought she was being cautious by setting the cruise control and
maintaining a safe consistent speed in the rain. But the highway
patrolman told her if the cruise control is on when your car begins to
hydro-plane and your tires lose contact with the pavement, your car
will accelerate to a higher rate of speed making you take off like an
airplane. She told the patrolman that was exactly what had occurred.

The patrolman 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, along with the airbag warning. We tell our teenagers to set
the cruise control and drive a safe speed - but we don't tell them to use
the cruise control only when the pavement is dry.

The only person the accident victim found who knew this (besides the
patrolman), was a man who had had a similar accident, totaled his car
and sustained severe injuries.

[MagicRat]

If one is on a VERY slippery surface, cruise control can interfere with one's driving.

Imo this is more relevant for snow and ice-covered roads. A careful driver can feel when the driving wheels may break loose and start to slip. When this happens, one loses directional control, so one must lift off the gas pedal immediatly to allow the wheels to grip again and slow thew car down gently. If one has the cruise control on, one cannot feel and react to this slippage as easily, so a crash is more likely.

However, Imo the tone of this warning is excessively sensationalistic and somewhat inaccurate. Cars generally do not launch themselves into the air just because they start to slide.

Also, good tires generally do not hydroplane either, unless they hit standing water (big puddles) at higher speeds. So, imo, cruise control is fine on a wet road so long as one is not driving too fast for conditions and there are no big puddles.

[shorod]

I agree that you have to drive for the conditions and keep up on maintenance (including tires), and that this spam e-mail is certainly sensationationalized. Cruise control uses wheel/axle speed to determine if it needs more or less throttle to maintain speed. If the cruise is set at 50 mph and the wheel starts to slip, it will still be spinning at 50 mph even though the car may be going a speed lower than that. The cruise control will not know that the car is travelling less than the set speed and therefore will not apply more throttle.

I feel the prudent warning would be to sensationalize the negative effects of talking on a cellular telephone while driving (hands-free or not), texting while driving, shaving while driving, etc. It seems people perform these bad habits regardless of environmental conditions (day, night, dry, rainy, snowy, doesn't seem to matter).

-Rod

[curtis73]

This is a complete load of bunk. First of all, cruise control wouldn't automatically apply more gas when you hydroplane, in fact it would apply less. Even so, I don't care if you floor it while hydroplaning, the car won't suddenly overcome the physics of gravity and launch the car into the air.

Cruise control is a computer controlled function that maintains speed. As you go up a hill and it senses the loss of speed, it applies more accelerator to maintain. I don't care how much traction you lose, the computer will still try to maintain that speed. It doesn't randomly accelerate when it encounters slip, it DEcelerates to maintain the same wheel speed.

your tires lose contact with the pavement, your car
will accelerate to a higher rate of speed making you take off like an
airplane. She told the patrolman that was exactly what had occurred.

Puh-leeze. Since when could rain and a computer-controlled throttle make you violate the laws of physics?

[Kriegar]

I saw a Gremlin do a complete backflip on the interstate during a heavy rain in Arkansas.

If you had ever experienced cruise control in operation during wheel slippage, you would know that it cycles. It cycles exceeding the st limit, cycles down to the speed you are travelling at, which is now slower than the set, and then cycles again, ad infinitum.

In an auto with an open rear end, this is handlable, but if the rear end locks posi, it can be extremely dangerous.

In any event, rain and hyroplaning, are extremely different things in tornado alley than they are, say, in the northeast. And speeds on the interstates are likely NEVER anything that would be considered reasonable, nor prudent, during those events.