1: Dalton to VT line in Heath via Savoy and Charlemont.
2: North Adams
1: In the 1930 ALA, this route is non-existent. Not as in numbered differently; the roads don’t even appear. Being that this is in the heart of the Pioneer Valley, it’s not all that suprising. The roads do show, unnumbered, on my 1936 map. The first indication of an 8A, which follows the same route as it does now, is on my 1950 map.
2: This first shows up on a 1950 Shell map. It basically covered the same start and end points as it does now, but takes the route of what is now MA 8. Only a few maps after that show 8A, however any that make a clear differentiation between road classes show 8 using what is now 8A to enter North Adams. The two routes appear to have been swapped in 1974 or 1975.
Yes, I see the small dot that indicates there’s another part of 8A near Dalton or Pittsfield. Not sure what it is – I’ll have to go look at the source data.
In my opinion, MA 8A is the state only true dual route. The difference between a dual route and a split route is that for a split route, one could imagine a semi-resonable connection between the two. In this case, the routes parallel each other.
Dan Vincent’s MA 8A page