There are two point data layers available
- Exits has points for every ramp at an interchange. The points will eventually be located at the gore point (where the ramp leaves the mainline) but currently many points are still clustered around the cross road.
- Interchanges has one point representing all the ramps. The point is located on the primary side of the route at the point where the second route crosses.
The locations of the interchanges were digitized from the Commonwealth of Massachusetts 1:5000 color orthophoto imagery to create the downloadable shapefile.
This data is current as of July 2013