This statewide point data layer represents milepost locations on numbered routes throughout the state, with one point for each sign marking the mileage along Interstate, US and state highways.
This layer was developed by the Massachusetts Department of Transportation (MassDOT) Office of Transportation Planning GIS Services group. MassGIS added the LABEL, TOWN and ZIP fields and projected the data to the Mass. State Plane Mainland meters coordinate system.
MassGIS stores the data as MAD.MILEPOSTS.
The point attribute table contains the following populated fields:
|ROUTE_ID||Route number, with administrative type prefix and directional indicator suffix. Prefixes are: "I" (Interstate), "US" (US Route), and "SR" (State Route).|
|MEASURE||The measure in miles along the route where the sign is located|
|MILE_POINT||Mile distance as posted on physical sign|
|GPS_X||X coordinate of the sign in Mass. State Plane Mainland meters, as recorded by GPS.|
|GPS_Y||Y coordinate of the sign in Mass. State Plane Mainland meters, as recorded by GPS.|
|LABEL||Used by MassGIS to simplify display where markers exist on both sides of a highway. LABEL = "Y" will draw only one point with the same mile measure on a route.|
|TOWN||Name of municipality in which the sign is located.|
|ZIP||ZIP Code in which the sign is located|
MassDOT maintains the original dataset, which may be viewed and downloaded at its Open Data Portal page.