**In Montana the maximum speed limit is 80 mph (129 km/h). Montana’s secondary roads have speed limits posted at 70 mph (113 km/h) and at night 65 mph (105 km/h). For trucks the speed limit is posted at 60 mph (97 km/h) and at night is 55 mph (89 km/h).**

Other speed limits in Montana are 25 mph (40 km/h) in a school zone, 30 mph (48 km/h) in a residential district, 35-45 mph (56-72 km/h) on boulevards, 55 mph (89 km/h) on traffic-light highways, 65-70 mph (105–113 km/h) on rural divided four-lane highways, and 55-70 mph (89–113 km/h) on two-lane undivided highways.