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Kansas driving lesson · Special Driving Situations

Night driving and flooded roads

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

Read time
3 minutes
Course unit
Special Driving Situations
Checkpoint questions
6
Source pages
90, 91

At night your headlights limit how far you can see, so you need to use them well and avoid being blinded by others. Flooded roads are a different trap: water hides how deep it is and what's under it.

Know the rule

Use your high beams whenever there are no oncoming vehicles. High beams let you see twice as far as low beams.

Handbook p. 90 ↗

Know the rule

Dim your high beams whenever you come within about one block of an oncoming vehicle.

Handbook p. 91 ↗

Know the rule

If an oncoming driver keeps high beams on, flash your headlights once quickly. If they still don't dim, look toward the right side of the road. Never keep your brights on to 'get back' at them.

Handbook p. 91 ↗

Use low beams when:

  • Following another vehicle
  • In heavy traffic
  • In fog
  • When it's snowing or raining hard
Handbook p. 91 ↗

Seeing better at night:

  • Avoid looking directly into oncoming headlights, which can cause momentary blindness
  • Glance well ahead of your headlight beams for dark shapes on the road
  • Glance left and right to find the pavement edge and hazards from the sides
  • Don't wear sunglasses or colored glasses at night or on dark days
  • Use fog lights, if you have them, in fog, snow or rain
Handbook p. 91 ↗

Know the rule

Flash floods can come rapidly and unexpectedly, within minutes or hours of heavy rain. Be cautious at night, in storm season and wherever flooding is common.

Handbook p. 91 ↗

How much water it takes

How much water it takes
WaterEffect
6 inchesReaches the bottom of most cars; loss of control or stalling
2 feet of rushing waterCan carry away most vehicles
Handbook p. 91 ↗

Flooded roads:

  • Don't drive through flooded areas; turn around and find another route
  • Even water that looks shallow can hide dips or a washed-out road surface
  • If there's no other route, go to higher ground and wait for the water to go down
Handbook p. 91 ↗

Put it into practice

After a thunderstorm you reach a low spot where water covers the road. It looks only a few inches deep. Don't try it: 6 inches can stall your car, and the road underneath may be washed out. Turn around.

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.

When should you dim your high beams for an oncoming vehicle?
  1. About one block from the oncoming vehicle
  2. Only after they pass you
  3. Only within 50 feet
  4. Only if they flash their lights first

Answer: About one block from the oncoming vehicle

Dim your high beams when you are within about a block of an oncoming vehicle to avoid blinding them.

Handbook p. 91 ↗
If an oncoming driver fails to dim their high beams, what should you do?
  1. Keep your high beams on to retaliate
  2. Look toward the center line
  3. Look toward the right side of the road
  4. Flash your high beams repeatedly at them

Answer: Look toward the right side of the road

If the other driver does not dim their lights, look toward the right side of the road so you are not blinded by their headlights.

Handbook p. 91 ↗
About how many inches of water on a roadway is enough to reach the bottom of most passenger cars?
  1. 24 inches
  2. 12 inches
  3. 1 inch
  4. 6 inches

Answer: 6 inches

The handbook states just 6 inches of water can reach the bottom of most passenger cars, causing stalling or loss of control.

Handbook p. 91 ↗
About how much rushing water can carry away most vehicles?
  1. 6 inches
  2. 2 feet
  3. 6 feet
  4. 10 feet

Answer: 2 feet

Just 2 feet of rushing water is enough to carry away most vehicles, according to the handbook.

Handbook p. 91 ↗
If you see a flooded roadway ahead, what should you do?
  1. Turn around and find another route
  2. Proceed if other cars have already crossed
  3. Drive through slowly to test the depth
  4. Follow the centerline through the water

Answer: Turn around and find another route

The handbook is explicit: do not drive through flooded areas — turn around and find another route.

Handbook p. 91 ↗
It is safe to drive through a flooded roadway if the water looks shallow enough to cross.
  1. True
  2. False

Answer: False

Even water that looks shallow can hide dips or have already damaged the road surface underneath, so you should never attempt to cross.

Handbook p. 91 ↗
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