High Quality Content by WIKIPEDIA articles! The following is a List of numbered routes in Delaware, consisting of Interstate highways, U.S. routes, and state routes. The Delaware Department of Transportation is responsible for maintaining numbered roads in Delaware. State routes in Delaware use the circular highway shield. Delaware`s numbering system mirrors that of U.S. Highways in that odd numbered highways travel north-south and even numbered routes go east-west. The numbers increase in value as one goes south and west respectively. There are some exceptions, however, mainly with routes from other states keeping their number as they enter Delaware, hence breaking the pattern.