Cruise control

Cruise control is designed to maintain a fairly constant vehicle speed without the need for driver input. 

Advantages are that it: 
  • largely eliminates the need for the driver to monitor vehicle speed. 
  • can have a beneficial effect on fuel consumption by reducing sudden throttle movements 
  • can reduce driver distraction by removing the need to constantly monitor vehicle speed 
Its main disadvantage is that it can increase driver reaction time very slightly.
Conventional cruise control systems have no connection to the vehicle’s brakes and therefore can’t prevent a vehicle over-speeding when travelling down a steep hill.
For safety reasons most systems will not operate below about 60 km/h.

Safe use of cruise control

Cruise control should not be used: 
  • in the city 
  • in heavy traffic 
  • in wet or slippery conditions 
  • where braking and / or lower speeds are required to negotiate bends.

Intelligent cruise control systems Vs conventional cruise control systems

Intelligent cruise control systems use radar to sense vehicles on the road ahead to maintain a safe following distance. Intelligent systems can also apply the vehicle’s brakes to maintain a safe following distance or prevent the vehicle over-speeding when descending hills.
Conventional cruise control systems can’t do this and the driver still must monitor following distance and road speed and apply the brakes where necessary.

Fuel consumption benefits

US studies suggest fuel savings may be in the order of 7 to 14 percent however these figures must be considered in their proper context. An experienced and fuel economy conscious driver may be able to drive more economically without using cruise control, though less skilled drivers would probably derive some benefit from its use.  The actual benefit achieved will therefore depend on the driver’s skill level.

Cruise Control legend and myths

For several years the internet has circulated warnings about the dangers of using cruise control in wet or icy conditions.  While there is a grain of truth in these warnings, they generally greatly exaggerate the issue and provide inaccurate information.  Most use near identical wording and American terminology.  Many use US place names while others tell the same story but have been ‘Australianised’, presumably to give greater local credibility.  

Here is an example:
A 36-year-old female had an accident several weeks ago and totalled her car. A resident of Kilgore, Texas, she was travelling between Gladewater & Kilgore. It was raining, though not excessively, when her car suddenly began to hydroplane 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 had thought she was being cautious by setting the cruise control and maintaining a safe consistent speed in the rain.

The Facts

The true statement here is that you shouldn’t use cruise control in wet / slippery conditions.  But the claims that it “literally flew through the air”, “took off like an aeroplane” and “accelerated to a high rate of speed” are at best uniformed nonsense.

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