Idaho Permit Test: Speed Limits Practice Questions

Correct answer: Drive at a speed reasonable and prudent for conditions

Idaho's basic rule requires a speed that is reasonable and prudent for current conditions, even below the posted limit.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: Yes, if it's unsafe for conditions or so slow it impedes traffic

Driving too fast for conditions, or so slowly that you impede the safe flow of traffic, violates the basic rule even if you are under the posted limit.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: 35 mph

Idaho's default maximum in residential, business, or urban districts is 35 mph unless otherwise posted.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: 75 mph

The interstate maximum is 75 mph unless posted otherwise; up to 80 mph may be allowed where signs permit.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: 65 mph

Vehicles may not exceed 65 mph on state highways; 70 mph may be allowed where posted.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: 80 mph

Where posted and conditions allow, vehicles may travel up to 80 mph on rural interstates.

Source: Traffic Laws & the Rules of the Road – Freeway Driving

Correct answer: 65 mph

Where designated and as weather permits, vehicles may travel up to 80 mph on rural interstates and up to 65 mph on urban interstates, unless otherwise posted.

Source: Traffic Laws & the Rules of the Road – Freeway Driving (Idaho Driver's Manual, July 2026, PDF p. 83)

Correct answer: Up to 15 mph

Idaho lets cars, pickups, and motorcycles not towing anything exceed the limit by up to 15 mph to pass a slower vehicle on such roads, then slow back down; not in work zones.

Source: Traffic Laws & the Rules of the Road – Passing

Correct answer: In work zones

The exception to exceed the limit while passing does not apply in work zones, and it requires a two-lane road posted at 55 mph or more.

Source: Traffic Laws & the Rules of the Road – Passing

Correct answer: You may not stay in the far left lane if you impede lawful traffic

Idaho prohibits staying in the extreme left lane for a period that impedes other traffic traveling at a lawful speed.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: An enhanced, fixed penalty

Violating a designated work zone speed limit can bring an enhanced, fixed penalty; fines are increased where signs indicate.

Source: Traffic Laws & the Rules of the Road – Speed Limits

Correct answer: 55 mph

Most tires grip a wet road up to about 35 mph, but at around 55 mph they may ride on a film of water and lose all contact.

Source: Sharing the Road – Rain & Hydroplaning

Correct answer: 100 feet

Low beams light about 100 feet ahead (high beams about 350 feet). Drive slowly enough to stop within the distance you can see.

Source: Sharing the Road – Night Driving

Correct answer: Taking part in a race, speed exhibition, or speed contest

Engaging in any vehicle race, speed exhibition, or speed contest on a public road, street, or highway is illegal in Idaho.

Source: Traffic Laws & the Rules of the Road – Speed Limits