Found some great wheel chocks;
HGS-YF is a large heavy duty molded aluminum wheel chock with rubber feet to reduce road compression. It is powder coated yellow for maximum visibilty. It has a heel-to-toe length that allows for a steeper line of force between axle and rear teeth, and therefore, an enhanced coefficient of friction.
HGS-YF features a hand-grab opening which allows for fast placement and retrieval. A flanged base allows for a full range of bracket options.
HGS-YF is commonly used for loading docks, utility vehicles, and firetrucks.
https://www.chocks.com/product/hgsyf
Have two pairs on order...
Bill