Lt. Robert Kimbrel, Bedford PD, summed it up very well in this local television news piece.
Please don't discharge yard clippings onto the roadways. This causes a very real hazard for motorcyclists and those riding bicycles.
Each year, cyclists are injured or killed when encountering grass on the highways. It is very slick for the narrow tires of these type vehicles.
18.2 -324 Virginia Code has the following section that can apply to grass clippings being in the roadways:......."nor shall any person throw or deposit or cause to be deposited upon any highway any soil, sand, mud, gravel or other substances so as to create a hazard to the traveling public."