What is the maximum speed limit for commercial vehicles in California?

speed limit for semi trucks

Certain commercial vehicles have the maximum speed of 55 mph on highways. These include:

  • Truck or tractor with three or more axles
  • Truck or tractor drawing another vehicle behind it
  • School bus with students inside
  • Farm labor vehicle with passengers inside
  • Vehicles carrying explosives

What to do when driving a big truck, bus or towing a vehicle?
If you are going to drive a big truck, bus or towing a vehicle, you must stay in the right-hand lane or a lane that is specially marked and designated for slower vehicles.  If you are driving on a road with four or more lanes, you may only drive at the two right lanes.