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Delaware driving lesson · Driving Skills & Safety

Following distance & space cushion

A 3-minute lesson from the Delaware 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
Driving Skills & Safety
Checkpoint questions
6
Source pages
125, 126, 127, 128

Rear-end crashes are very common, and space is your best protection. Keep a cushion ahead, behind and beside you so you always have time and room to react.

3 sec

Minimum following distance—the 'three-second rule' works at any speed

Handbook p. 126 ↗

The three-second rule:

  • Watch the rear of the vehicle ahead pass a sign, pole or other fixed point
  • Count 'one-one-thousand, two-one-thousand, three-one-thousand'
  • If you reach the point before you finish, you're too close—drop back and count again
Handbook p. 126 ↗

You may need four seconds or more when:

  • The road is slippery
  • The driver behind you wants to pass
  • Following a motorcycle
  • Following trucks, buses, vans or vehicles towing that may not see you
  • You have a heavy load or are pulling a trailer
  • It's hard to see because of darkness or bad weather
  • You're being followed closely
  • Following emergency vehicles, or approaching railroad crossings
  • You're stopped on a hill (the vehicle ahead may roll back)
Handbook p. 126 ↗

Know the rule

If you're being tailgated, move right if there's a lane. If not, wait until the road ahead is clear and slow down gradually so the tailgater drives around you. Never slow down quickly to discourage a tailgater.

Handbook p. 127 ↗

Know the rule

Help others keep space behind you: hold a steady speed and signal early. Stop to pick up or drop off passengers out of traffic, and if you're driving slowly, pull over when safe to let others pass.

Handbook p. 127 ↗

Space to the side:

  • Avoid driving right next to other vehicles on multi-lane roads—move ahead or drop back
  • On two-lane roads, don't crowd the center line; the center of your lane is generally safest
  • Make room for vehicles entering the road—move over a lane if no one's beside you
  • Leave extra space next to parked cars, pedestrians and bicycles, especially children
  • Don't share a lane with a pedestrian or bicyclist—wait to pass in the next lane
Handbook p. 127 ↗

Know the rule

Split the difference between two hazards, but if one is more dangerous (such as an oncoming tractor-trailer), leave a little more room on that side. With a pedestrian or cyclist, give the vulnerable user the extra room.

Handbook p. 128 ↗

Put it into practice

A car cuts in ahead of you on I-95, leaving a two-second gap. Ease off the gas until the gap grows back to at least three seconds—and if the road is wet, make it four.

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.

Under the standard following-distance rule, how many seconds of space should you keep behind the vehicle ahead?
  1. One second
  2. Three seconds
  3. Two seconds
  4. Five seconds

Answer: Three seconds

The three-second rule is the standard following distance that works at any speed.

Handbook p. 125 ↗
You should use a four-second following distance in which of these situations?
  1. On a straight, dry, familiar road
  2. When traffic is very light
  3. When driving in daylight
  4. When the road is slippery

Answer: When the road is slippery

Slippery roads require more stopping distance, so a four-second following distance is recommended.

Handbook p. 126 ↗
Which of these situations calls for an increased four-second following distance instead of three seconds?
  1. When traffic is very light
  2. When driving on a familiar road
  3. When you are pulling a heavy trailer
  4. When the road is dry and straight

Answer: When you are pulling a heavy trailer

Extra weight from a trailer or heavy load increases stopping distance, so a four-second following distance is recommended.

Handbook p. 126 ↗
If another driver is tailgating you, the safest response is to
  1. brake suddenly to discourage them
  2. speed up to create distance
  3. turn on your hazard lights
  4. move to the right if possible and avoid braking suddenly

Answer: move to the right if possible and avoid braking suddenly

If tailgated, move right if there is a lane, or gradually reduce speed; never brake suddenly, which increases your risk of being hit.

Handbook p. 127 ↗
Why should you leave extra following distance when behind a bus, van, or vehicle pulling a trailer?
  1. They always brake later than cars
  2. They have shorter stopping distances
  3. They are required to drive slower
  4. Their drivers may not be able to see you directly behind them

Answer: Their drivers may not be able to see you directly behind them

Drivers of large vehicles or those towing trailers may not see you directly behind them and could stop suddenly without warning.

Handbook p. 126 ↗
The three-second following rule works at any speed, not just on highways.
  1. True
  2. False

Answer: True

The three-second rule is designed to work regardless of your driving speed.

Handbook p. 125 ↗
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