Street Centerline Segments. A single line representing each street in the District, segmented at major blocks to preserve geocoding integrity. They follow the general trend of the street and do not deviate due to parking lanes, turning lanes, etc. and contain address ranges for geocoding. The street GIS database includes only the major road types: street centerline. All DC GIS data is stored and exported in Maryland State Plane coordinates NAD 83 meters. This layer contains complete theoretical address ranges.