You’d think there’d be a way to make up large buckets or bins of murky/dirty water (think chocolate milk consistency) and use a power washer to lightly apply it to the road surface so when it drys it leaves a thin coating of tan/khaki.brown dirt on the road. Then just hose it off later or wait for it to rain.
I like the muddy water approach! It would combine well with tarps, if needed.
Sand ain’t cheap. Road crush would be cheaper and probably similar to a macadamized surface, but may be difficult to remove with out marking up the surface. A Mulch as posited by the OP does make sense.
What about painting it brown with whatever paint and then rather than removing it, just re-paint it asphalt color?
So - here’s what we did:
Five 12 x 15’ canvas tarps were dyed a dark brown color and then spread out flat. A clay slurry about the consistency of heavy cream was then poured over the tarps and spread out with pushbrooms to saturate the canvas and leave ~1/8” or less of mud on the surface. The clay was allowed to dry a bit, and then the surface was covered with a mixture of peat moss, sawdust, dry grass clippings, and other dusty duff. This was allowed to dry completely, and then the loose dry material was raked off and stored for reuse.
The tarps were rolled onto old cardboard carpet tubes, with the fuzzy sides in. On the shooting day, they were unrolled and laid out, shingled one over the other by a few inches. The wrinkles were smoothed out and the ‘seams’ were hidden by scattering more duff mixture over the tarps. With the mud coating, the tarps were heavy enough to hold themselves down against moderate winds. They conformed well to irregular ground, and even looked good running up over a curb from the street. The canvas weave and the fibrous matter helped to keep the clay layer stuck down intact despite being rolled up and moved from place to place multiple times and having dozens of people walking over it for many takes. All in all they were a success - or at least they seemed so at the time of filming. I guess we’ll see what they look like in the final edit.