Street Intersection Points. The dataset contains locations and attributes of Intersections, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. The Intersection Points - MAR is primarly derived from DC Department of Transportation's (DDOT) Intersection Table in their Street Spatial Database (SSD). Regular at grade intersections (TYPE = 'REGULAR') as well as overpasses (TYPE = 'OVERPASS'), underpasses (TYPE = 'UNDERPASS') and ramps (TYPE = 'RAMP') are included. The overpasses, underpasses and ramps are based on street centerlines from DDOT.