Passing and slow vehicles

Key points

1. Do not pass within 100 feet of an intersection or a railroad crossing unless traffic control devices allow it.

   Source: Handbook p. 76

   “Within 100 feet of an intersection, unless otherwise indicated by traffic-control devices Within 100 feet of a railroad crossing”
   Idaho Driver's Handbook, Handbook p. 76

2. Do not pass a stopped school bus, or a vehicle stopped for a pedestrian at a crosswalk.

   Source: Handbook p. 77

   “When a school bus is stopped to load or unload passengers When a vehicle ahead of you has stopped at a marked or unmarked crosswalk to let a pedestrian cross”
   Idaho Driver's Handbook, Handbook p. 77

3. A car, pickup or motorcycle not towing may go up to 15 mph over the limit to pass a slower vehicle on a two lane road.

   Source: Handbook p. 77

   “If you are driving a passenger vehicle, motorcycle or pickup, not towing another vehicle, you may exceed the posted speed limit by up to 15 miles per hour while passing another vehicle that is traveling below the posted speed limit on a two-lane roadway.”
   Idaho Driver's Handbook, Handbook p. 77

4. That exception applies only where the limit is 55 mph or more, and never in work zones.

   Source: Handbook p. 77

   “The posted speed limit must be 55 miles per hour or greater. This does not apply in work zones.”
   Idaho Driver's Handbook, Handbook p. 77

5. Pass on the right only when the vehicle ahead is turning left, or on a road with two or more lanes your way.

   Source: Handbook p. 77

   “When the vehicle you're overtaking on a two-lane, twoway road is signaling to turn left On a one-way or multi-lane street with two or more lanes going your direction”
   Idaho Driver's Handbook, Handbook p. 77

6. Complete a pass before coming within 200 feet of oncoming traffic.

   Source: Handbook p. 78

   “Complete a pass before coming within 200 feet of oncoming traffic.”
   Idaho Driver's Handbook, Handbook p. 78

7. When being passed, move right in your lane and do not speed up.

   Source: Handbook p. 78

   “Move to the right side of your lane to give them more room and a better view of the road ahead. Don't speed up.”
   Idaho Driver's Handbook, Handbook p. 78

8. A slow vehicle delaying 3 or more vehicles on a rural or two lane road must pull off where safe.

   Source: Handbook p. 79

   “Any vehicle traveling slower than the normal speed of traffic delaying three or more other vehicles in a rural area or on a two-lane highway must turn off the road wherever safe to let the other vehicles pass.”
   Idaho Driver's Handbook, Handbook p. 79

Numbers to know

Recognize these signs

3 questions from the Idaho practice test

1. 1. Does Idaho's special passing allowance apply on a two-lane road posted at 45 miles per hour?

   1. No, because passing is never allowed on two-lane roads
   2. Yes, every two-lane road qualifies
   3. Yes, but only during daylight
   4. No, the posted limit must be 55 miles per hour or greater
   Show answer

   No, the posted limit must be 55 miles per hour or greater. The special passing allowance is limited by the posted speed condition, so a 45 mile per hour road does not qualify. The rule is not available on every two-lane road, and it does not ban all passing on such roads. Daylight alone also does not create eligibility. Before considering the allowance, read the sign and confirm that the roadway and vehicle meet every condition for the exception.

2. 2. Which vehicle qualifies for Idaho's special passing speed allowance when the other conditions are met?

   1. A bus carrying passengers
   2. A pickup towing a boat trailer
   3. A commercial semitrailer
   4. A motorcycle that is not towing anything
   Show answer

   A motorcycle that is not towing anything. Idaho's passing exception is aimed at a passenger vehicle or motorcycle that is not towing another vehicle. A motorcycle traveling alone fits that vehicle condition. The pickup with a trailer and the semitrailer both add towing or commercial-vehicle concerns that remove them from the allowance described here. Even an eligible motorcycle must still pass lawfully, have a clear view, and obey the roadway's other restrictions.

3. 3. Can driving too slowly become a violation of Idaho's basic speed rule?

   1. Yes, but only when a police officer measures the speed
   2. No, only speeds above the limit can violate the rule
   3. No, slow driving is illegal only on interstates
   4. Yes, if the slow speed impedes the safe flow of traffic
   Show answer

   Yes, if the slow speed impedes the safe flow of traffic. Idaho's basic rule applies in both directions. A driver who goes so slowly that normal traffic is disrupted can violate the law even without exceeding a posted maximum. The interstate-only choice is too narrow, and a speed measurement is not the condition stated by the handbook. Keep right when appropriate, monitor the traffic you are affecting, and adjust for hazards without creating an unnecessary obstruction.

Source: the Idaho Driver's Handbook, Traffic Laws & the Rules of the Road. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.