I don't think your insurance company is going to go out and measure the skids. My professor last semester was a accident investigator who went out to the scene to measure skids, and find the road surface firction value. alot of information can be found out by using skid marks. You will need a drag sled to find the friction surface value of the street for the caculation. He said he never investigated an wreck that was just a fender bender he charges $250.00 an hour most of his clients where major injury or fatals.