Following distances — Illinois Permit Test

Following distances on the Illinois permit test — 4 rules, each with the reason behind it and a question on it while it is fresh.

The rules

Following too closely, which is tailgating, causes most rear-end crashes.

A rear-end crash is a following distance problem every time. Naming the cause is what makes the three-second rule worth using.

Following a vehicle too closely, or tailgating, is the cause of most rear-end crashes.

Illinois Rules of the Road 2026, p.83

The three-second rule sets a safe following distance: when the vehicle ahead passes a fixed object, a driver counting should not reach that object before the count of one-thousand-three.

Counting works at any speed, which a fixed number of car lengths does not. The object is whatever is beside the road ahead.

Use the three-second rule to determine a safe following distance. To use the three-second rule, select a fixed object on the road ahead, such as a sign, tree, or overpass. When the vehicle in front of you passes the object, count “one-thousand-one, one-thousand-two, etc.” Your vehicle should not reach the object before the count of one-thousand-three. If this occurs, you are following too closely.

Illinois Rules of the Road 2026, p.83

The three-second rule applies on a good road in good weather, and a driver should increase the following distance further where the road or weather is poor.

Three seconds is the floor, not the answer. Rain, snow or a rough surface all need more than it.

The three-second rule also applies to your vehicle speed when you are on a good road and during good weather conditions. If the road and/or weather conditions are not good, increase your following distance even more.

Illinois Rules of the Road 2026, p.83

A driver being tailgated should move to another lane or slowly pull off the road and let the other vehicle pass.

Braking to teach a tailgater a lesson removes the gap they were relying on. Letting them past is the only thing that works.

If you are being tailgated, move to another lane or slowly pull off the road and allow the vehicle to pass.

Illinois Rules of the Road 2026, p.83

On the test

What causes most Illinois rear-end crashes?

Following the vehicle ahead too closely. A rear-end crash is a following distance problem every time. Naming the cause is what makes the three-second rule worth using. Illinois Rules of the Road 2026, p.83: “Following a vehicle too closely, or tailgating, is the cause of most rear-end crashes.”

How this works

Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.

You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.

Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.

What it costs

  • One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
  • Free to start: a 10-question test and the first section of cards. No sign-up and no account.
  • Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
  • Every level up to Prepared — 3 tests passed in a row.
  • Do the work, fail the real exam, and we refund you.

All Illinois permit topics

Where these come from

Every rule here is checked against Illinois Rules of the Road 2026, published by the Illinois Secretary of State, and against the state code itself. Last checked 2026-09-21.