When one drives on the Bonneville Salt Flats when the salt is wet, the salt gets thrown onto a vehicle in the same manner that snow does. And just as snow sometimes falls off of a car onto the ground, so does salt. This produces little piles of salt on streets and in parking lots (note the white spots at the bottom of the photo). The driver of this truck probably went to the local self-serve car wash to get rid of the corrosive mineral. This is in the parking lot of Smith’s grocery store.
