Using Wheel Chocks
Utility fleets need to use wheel chocks to protect their trucks from accidentally rolling down a hill because of truck malfunction or possibly the driver forgetting to set the brake or put the truck into park. These things should not happen, of course, yet when wheel chocks are used, it can't. OSHA guidelines even specify that a truck should always have a parking brake in place even before the chocks are in place.
The beautiful thing is that chocks are usually lightweight, made of urethane, and can be tied together with a rope, wire or chain for easier placement and removal. Some of the heavier chocks are made of recycled rubber, and what you order will depend on your preferred material. Either way, both substances are resistant to oils, chemicals and are weather resistant, and can be used from either side of the tire. The pressure of the tire pressing against the chock, along with the incline, make it balanced and can hold the vehicle in place if the brake is forgotten.
Roadblock Wheel Chocks come in both rubber and urethane and won't damage the road or the tire. While the rubber chocks are black, the urethane ones are bright safety orange for visibility to both the driver and the passers-by to alert them that a service vehicle is working at that location.
Wheel Chock Warnings
With all chocks come warnings. The chocks must be appropriate for the vehicle for which they are being used. They can come in all sizes and heights for different tire sizes. You probably don't need the monster version that accommodates 400 tons of weight and has to be transported with a cart, but if you're in the mining or construction industry, that's what you'll need. Other warnings are that they should not be placed next to the wheels until the parking brakes are engaged and tested. The chocks should fit snuggly against the tire and road in pairs and in the direction of the grade.
The final warnings should be followed when leaving - don't forget the chocks and don't drive over them, for they may damage the truck or the chocks.