The District of Columbia

Street Centerlines

Street Centerlines

by District Department of Transportation on 20120407

Keywords
About: transportation, Planimetrics, road, Interstate, location, Street Centerline, Street
Taking place at: Washington, DC, District of Columbia

Abstract


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.

METADATA CONTENT IS IN PROCESS OF VALIDATION AND SUBJECT TO CHANGE.

Purpose

This data set was created to act as a basis for public and private institutions to improve their policy and decision making; promote economic development; and enhance the quality of life for residents and businesses.

Use constraints

Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.

Point of contact

GIS Data Coordinator
in D.C. Office of the Chief Technology Officer

441 4th St NW, Suite 930 South
Washington DC, 20001, USA

fax: (202) 727-5660
hours: 8:30 am - 5:00 pm

Credits

DC District Department of Transportation

Data accuracy

Accuracy
Validated by source and/or responsible agency. The original centerline attribute accuracy was tested by manual comparison of the digital orthos/aerial photography with the hard copy plots. In addition, several computer quality control programs were run on the accompanying digital data.

Logical consistency
Validated by source and/or responsible agency.

Completeness
Validated by source and/or responsible agency.

Horizontal positional accuracy
Validated by source and/or responsible agency. The original centerlines, as part of the photogrammetric mapping effort, are captured to a planimetric base that meets National Map Accuracy standards for digital mapping at a 1 inch equals 83.33'.

Vertical positional accuracy
N/A

Lineage / Sources

  • Washington DC GIS project
    CD-ROM, SIS data
    DD1
    by Dewberry Davis, LLC, Unknown
  • Street Spatial Database
    Database, location and attributes
    Street Spatial Database
    by District Department of Transportation (DDOT) - Spatial Database System Division, 2005
Lineage / Processes

in Dewberry Davis, LLC

8401 Arlington Blvd.
Fairfax VA, 22031, USA

hours: Regular office hours

SIS Automation

This methodology describes the original centerline capture as part of the 1999 planimetrics:

Step 1 EDMD, D&D, NCPC and designated representatives of DC DPW will meet to accomplish the presentation of the listing of government furnished material that are needed by D&D. Then, set up conventions for the creation of intersection nodes, for attribution, for reporting of omissions, errors, or other QC issues in the SIS data to DC DPW and NCPC. These conventions will be tested and validated during the pilot project.

Step 2 For each contiguous block of centerlines, D&D will extend curb lines through street intersections and generate intersection nodes consistent with DPW
guidance established in step 1.

Step 3 Where two or more nodes are present that comprise a single intersection (e.g., two multi-street centerlines that intersect with four nodes), D&D will cluster those nodes and identify an intersection centroid for linking SIS files of street names, address ranges, etc.

Step 4 D&D will overlay the SIS files and conflate them to match the centerlines, nodes, and multi-node centroids. Because of anticipated SIS shortcomings, such as identified in D&D's Washington GIS, Pilot Project Final Report, dated June 30, 1997, this conflation will normally be performed manually.

Step 5 D&D will overlay the georeferenced SIS files over 1995 digital orthophotos and copies of the 1999 planimetric mapping provided by EDI to ensure that the new SIS files satisfy positional accuracy requirements.

Step 6 D&D will deliver one set of ARC/INFO export files (.e00) on CD-ROM to NCPC and will conduct a demonstration, on DPW equipment (PC ArcView), that the current INFO attributes work with the revised streetcenterline file coverage.

Step 7 D&D will conduct on-site field verification surveys (1)
direction (2) street name, (3) address ranges for each street segment between cross-streets, (4) number of lanes, (5) directionality of lane, and (6) lane usage.

Step 8 Addition of streets not digitized by EDMD.

Step 9 Correction of address ranges where streets are bisected by added streets.

Step 10 Correction of other SIS data errors observable from "windshield surveys."

Step 11 Provision of discrepancy lists, to NCPC, where SIS street names differ from those posted on street signs. D&D will not change the SIS files to match street signs that are verified in the field.

Distribution

Most DC GIS datasets can be downloaded from "http://dcgis.dc.gov" on the data center page. Orders can also be made by contacting OCTO GIS at "dcgis@dc.gov", especially for datasets not available for download.

Distribution liability
Acknowledgment of the DC Geographic Information Systems Program (DC GIS). The District of Columbia Government makes no claims as to the completeness, accuracy or content of any data contained hereon, and makes no representation of any kind, including, but not limited to, the warranty of the accuracy or fitness for a particular use, nor are any such warranties to be implied or inferred with respect to the information or data furnished herein.

Distributed by
GIS Data Coordinator
in D.C. Office of the Chief Technology Officer

441 4th St NW, Suite 930 South
Washington DC, 20001, USA

fax: (202) 727-5660
hours: 8:30 am - 5:00 pm

Entity

StreetSegmentLn

Attributes

  • SHAPE_LEN / ESRI
    Internal feature number.
  • STREETID / ESRI
    Street identifier for street name
  • ENDMEASURE
    end measure
  • SHAPE / ESRI
    Feature geometry.
  • STREETSEGI
  • FACILITYID
  • STREETTYPE
    Street Type
  • SOURCEID
    Source Identifier
  • REGISTERED
  • QUADRANT / ESRI
    Quandrant Name
  • Shape / ESRI
    Feature geometry.
  • DIRECTIONA
  • SEGMENTTYP
  • OBJECTID / ESRI
    Internal feature number.
  • FROMNODEID
    from node id
  • FROMADDRES
  • TOADDRESSL
  • FROMADDR_1
  • TOADDRESSR
  • BEGINMEASU
  • TONODEID
    to node id
  • UPDATETIME

Metadata

FGDC Content Standards for Digital Geospatial Metadata / FGDC-STD-001-1998 as of 20120618

Provided by
GIS Data Coordinator
in D.C. Office of the Chief Technology Officer

441 4th St NW, Suite 930 South
Washington DC, 20001, USA

phone: REQUIRED: The telephone number by which individuals can speak to the organization or individual.
fax: (202) 727-5660
hours: 8:30 am - 5:00 pm