Gas stations offer a unique set of problems that can be damaging to trench drain systems if not properly designed and installed. The loading, while slow speed, often has vehicles turning on top of the system which exerts dynamic loads that cannot be simply explained or tested with a simple grate load test machine. Combined with these dynamic loads are the exterior environment's thermal cycling and UV light. Gas station parking lots are often designed to run completely into a single trench drain or the drain may pick up run off from a very small area. Large gas stations running into one trench drain may need a large trench while others may only need to be a minimal size.