The Delaware State Route System consists of roads in the U.S. state of Delaware that are maintained by the Delaware Department of Transportation (DelDOT). The system includes the portions of the Interstate Highway System and United States Numbered Highways system located in the state along with state routes and other roads maintained by DelDOT. All roads maintained by the state are assigned a maintenance road number (reference number) that is only marked on little white markers at intersections and on auxiliary plates below warning signs approaching intersections. These numbers are only unique in a specific county; some roads can be designated with multiple road numbers, and numbers do not necessarily correspond to the signed Interstate, U.S., or state route numbers. DelDOT maintains a tot