The intensity of use by vehicles over the life of the pavement must be carefully assessed when selecting between grass or stone aggregate. Grass generally needs at least five hours of light each day if it is to survive. Cars parked on the grass every day for extended periods of time will block sunlight, killing the grass beneath. If parking is continuous, aggregate should be used in the opening instead of topsoil and grass. Aggregate should be used if regular watering and maintenance of the grass is not anticipated, since grass may die. Aggregate should also be used if oil drippings from parked cars is expected to be excessive. For intermittently used lots, overflow lots, or fire lanes, grass is recommended.

