Section 22406. Maximum Speed for Designated Vehicles

No person may drive any of the following vehicles on a highway at a speed in excess of 55 miles per hour:

(a) A motortruck or truck tractor having three or more axles or any motortruck or truck tractor drawing any other vehicle.

(b) A passenger vehicle or bus drawing any other vehicle.

(c) A schoolbus transporting any school pupil.

(d) A farm labor vehicle when transporting passengers.

(e) A vehicle transporting explosives.

(f) A trailer bus, as defined in Section 636.