In days of yore, (groan) the braking action at a lot of airfields was assessed by driving a Land Rover onto the runway, and standing on the brakes with a mu meter?..or whatever
I remember such use of a Land Rover in a distant place on a snow covered
gravel runway. The airfield radio guy, a farmer who worked part-time at the airport reported the "braking action as pretty good". During landing, while skidding all over the place, we saw some deep tire tracks in the snow. An inspection of said Land Rover, revealed snow chains on every tire! The guy had ripped through the snow into the gravel with the chains! No such luck on our old battered Fokker 27
o/c