Delaware State Route System

Delaware State Route System
Route markers for Interstate 95, U.S. Route 13, and Delaware Route 1
A map of state routes in the state of Delaware
System information
Maintained by DelDOT, USACE, and DRBA
Length	5,386.14 mi[3] (8,668.15 km)
Formed	April 2, 1917, state route numbers signed by 1936[1][2]
Highway names
Interstates	Interstate X (I-X)
US Highways	U.S. Route X (US X)
State	Delaware Route X (DE X)
Maintenance road numbers:	Road X
System links
Delaware State Route System List Byways

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 total of 5,386.14 miles (8,668.15 km) of roads, comprising 89 percent of the roads within the state. Some large bridges in the state are maintained by other agencies including the U.S. Army Corps of Engineers and the Delaware River and Bay Authority. Roads in the system include multilane freeways, multilane surface divided highways, and two-lane undivided roads serving urban, suburban, and rural areas. Some of the roads maintained by DelDOT are toll roads, in which motorists must pay to use.

The first roads in Delaware were Native American trails and unpaved roads laid out by colonial Swedish and English settlers. From this time, counties were responsible for roads. In the 19th century, private companies operated several turnpikes radiating from Wilmington. Thomas Coleman DuPont proposed a modern road in 1908 to run the north–south length of the state; this road evolved into the DuPont Highway, which was completed by the state in 1923. The Delaware State Highway Department was formed on April 2, 1917 to construct a state highway system in Delaware. Numbered routes came with the creation of the U.S. Highway System in 1926; state route numbers appeared 10 years later. In 1935, the state took over the remaining county roads. In the middle part of the 20th century, several major roads were widened into divided highways. The creation of the Interstate Highway System in 1956 led to the construction of 40 miles (64 km) of freeway in northern New Castle County, including the tolled Delaware Turnpike. The Delaware Route 1 (DE 1) limited-access toll road between Dover and Wilmington was fully completed in 2003, and was the largest public works project in state history.