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Kentucky driving lesson · Vehicle Control & Space

Curves, slippery roads & hydroplaning

A 3-minute lesson from the Kentucky course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.

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Read time
3 minutes
Course unit
Vehicle Control & Space
Checkpoint questions
4
Source pages
56

Speed limits assume ideal conditions. Curves, rain, snow, ice and standing water all cut traction, so you have to slow down before the trouble—not in the middle of it.

Know the rule

Slow to a safe speed before entering a curve—one that lets you apply slight, constant acceleration through it. Hard braking after you enter a curve can make the tires lose traction.

Handbook p. 56 ↗

Slow down even more for a curve when:

  • Traction is poor
  • You're following other vehicles
  • You can't see the end of the curve
Handbook p. 56 ↗

Know the rule

Reduce speed at the first sign of rain, snow, sleet or ice. Slippery roads mean longer stops and a greater chance of skidding in turns. Don't stop or turn quickly until you've slowed and your tires have regained traction.

Handbook p. 56 ↗

Know the rule

Excessive speed or going downhill on slippery roads can cause the vehicle to skid or hydroplane.

Handbook p. 56 ↗

Know the rule

On slippery roads, pump the brakes gently—unless your vehicle has anti-lock brakes, in which case apply steady pressure.

Handbook p. 56 ↗

Hydroplaning

When the steering tires ride up on pooled water, like water skis, so they no longer touch the actual road surface.

Handbook p. 56 ↗

Avoid hydroplaning:

  • Slow down in the rain or when water is pooled or puddled on the road
  • Keep your tires properly inflated
  • Keep good tread on your tires
Handbook p. 56 ↗

Know the rule

Don't drive through large bodies of standing water. If a road is flooded, find another route.

Handbook p. 56 ↗

Put it into practice

Rain starts on the parkway and water pools in your lane. Ease off the gas and slow down early, keep a firm grip, and avoid sudden braking or turning until your tires grip the road again.

Check your understanding

Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.

Hard braking right after entering a curve could cause the vehicle's tires to lose traction.
  1. True
  2. False

Answer: True

The manual warns that hard braking after entering a curve could cause tires to lose traction.

Handbook p. 56 ↗
Hydroplaning occurs when:
  1. The wheels lock under hard braking
  2. A vehicle's tires ride up on pooled water and lose contact with the road
  3. Brakes are applied too gently on dry roads
  4. Tire pressure is too low on dry pavement

Answer: A vehicle's tires ride up on pooled water and lose contact with the road

Hydroplaning happens when the steering tires ride up on pooled water, similar to water skis.

Handbook p. 56 ↗
On a slippery road, if your vehicle does NOT have anti-lock brakes, you should:
  1. Pump the brakes gently
  2. Pump the brakes as hard as possible
  3. Release the brakes completely
  4. Apply steady, hard pressure

Answer: Pump the brakes gently

Without ABS, pump the brakes gently on slippery roads rather than applying hard steady pressure.

Handbook p. 56 ↗
The best way to avoid traction loss from hydroplaning is to:
  1. Brake firmly when you reach standing water
  2. Slow down in the rain or on wet roads
  3. Lower your tire pressure for better grip
  4. Use cruise control to hold a steady speed

Answer: Slow down in the rain or on wet roads

The best way to avoid hydroplaning is to slow down in the rain or when the road has pooled water, and to keep tires properly inflated with good tread.

Handbook p. 56 ↗
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