Delaware mandates connected streets

The Delaware Department of Transportation (DelDOT), which has jurisdiction over most streets and roads in its state, is — like Virginia — requiring that new subdivision streets be connected to neighboring areas. Since March 2008, DelDOT has required new subdivision street systems to achieve a connectivity ratio of at least 1.4. That figure had been recommended by Reid Ewing in a report called “Mobility-Friendly Street Standards for Delaware.” The connectivity ratio is determined by counting the number of “street links” (stretches of street between intersections or dead ends) and dividing it by the number of “nodes” (intersections or dead ends) in the area that the streets serve. DelDOT is also requiring sidewalks along all subdivision streets — something not previously in its standards. Dead-end streets are generally being limited to a length of 200 feet; they used to be allowed to be 500 to 1,000 feet long. Developers may still install longer dead-end streets if they can show that they’re necessary. Theodore Bishop, assistant director of planning for DelDOT, says a committee is now examining the possibility of having the state devise a model of mixed-use development, which could serve as a guide throughout Delaware. In the great majority of states, subdivision streets are not regulated by state transportation departments. They’re overseen instead by counties or municipalities. Local governments increasingly are demanding more generously connected networks. Michael Knapp, a member of the Montgomery County (Maryland) Council, recently told The Washington Post that his county’s next master plan will stress connectivity, similar to Virginia’s.