Idaho Speed Limits – National Speed Limits in Idaho

The maximum speed limit on a freeway in Idaho is 80 mph rural (129 km/h), 65 mph (105 km/h) urban, and a 70 mph (113 km/h) truck speed limit. Generally two-lane and four-lane highways have 70 mph (113 km/h) speed limits, and roads with traffic lights are posted at 60 mph (97 km/h) or below.

The school zone speed limit in Idaho is 20 mph (32 km/h), except Grangeville, in which it is 15 mph (24 km/h).