Section 7020 - (9-25). Canopy Guard(a) Except as provided in subsection (d) of this section every haulage vehicle that is loaded by means of any device which employs a swinging boom to load the vehicle shall be equipped with a suitable canopy guard for the driver's seat.(b) The canopy guard shall be strongly constructed to afford adequate protection for the driver. It shall be of sufficient width and height so as not to hamper the movement of the driver or prevent his immediate escape from the vehicle in emergency.(c) The canopy shall be steel plate at least three-sixteenths inch thick. It shall be substantially supported by steel members of adequate strength attached to the frame or body of the vehicle.(d) A canopy guard is not required on any haulage vehicle which is provided with a cab so constructed that it will afford at least as much protection as a canopy guard.Cal. Code Regs. Tit. 8, § 7020