Driver's License Test Prep
Oregon Practice Speed Limits

The Oregon "basic rule" for speed says:

  1. A.
    The posted limit is only a suggestion under the basic rule.
  2. B.
    You may exceed the posted limit if traffic conditions are clear and safe.
  3. C.
    You must drive at exactly the posted speed limit, no more, no less.
  4. D.
    Drive at a speed reasonable and cautious for conditions, never over the posted limit. Correct
The Why

The answer is "Drive at a speed reasonable and cautious for conditions, never over the posted limit."

The basic rule requires you to drive at a speed that is reasonable and cautious for existing conditions, and it applies on all roads at all times. It does not permit driving over the posted speed limit; the posted number acts as a ceiling. The basic rule may further reduce your safe speed below that ceiling when conditions warrant (rain, fog, traffic, school children, etc.). Drivers drawn to B read the rule as permission to exceed the posted number when conditions look clear, though the manual states the rule does not allow driving over the speed limit.

Why the others miss

The traps in the wrong answers

A. The posted limit is only a suggestion under the basic rule.

Posted limits are enforceable. The basic rule operates in addition to (not instead of) posted limits. This answer treats posted limits as advisory. Posted speed limits are set in law and enforced; the basic rule applies alongside them, not in place of them.

B. You may exceed the posted limit if traffic conditions are clear and safe.

The basic rule explicitly does not allow driving over the posted speed limit, regardless of conditions. This answer treats the basic rule as authorizing speeds above the posted limit when conditions seem safe. The manual states the basic rule does not allow you to drive over the speed limit.

C. You must drive at exactly the posted speed limit, no more, no less.

The basic rule does not require driving at the posted limit; it requires a speed safe for conditions, which may be lower than posted. This answer reads the posted limit as a required exact speed. The manual defines the posted limit as the maximum considered safe, not a fixed required speed.

The Rule

This question tests your knowledge of Speed Limits in Oregon. Source: Oregon Driver Manual, "Speed Regulations - The Basic Rule Law," p.20..

More from this topic

Related Oregon questions

More than a book

You just took one Oregon question apart. The book does it for the whole test.

The Oregon book unlocks a free companion: an adaptive study plan, progress synced across your devices, a denser laminate cheat sheet, and a test-day walkthrough. Verify your copy once, usually in seconds; there's nothing extra to buy.

Get the book on Amazon

$18.99 paperback, free companion included.

Free study plan

Your free Oregon study plan

A short run of study emails for the Oregon DMV test: what to drill, the rules people trip on, and a final pre-test checklist. The printable cheat sheet is free to grab either way.

One email a few times a month. No spam, unsubscribe anytime. Privacy.