CA Veh Code Section 35655

(a)

No person shall drive a vehicle on any state highway when the weight of the vehicle and load is greater than the maximum weight which the highway will sustain. Violations of this subdivision shall be punished in accordance with the schedule of fines set forth in Section 42030.

(b)

Upon the trial of any person charged with a violation with respect to signs erected under Section 35654, proof of the determination and the maximum weight by the Department of Transportation and the existence of the signs constitutes prima facie evidence of the maximum weight which the state highway will sustain.