The Pike was also built through the poorest (and immigrant-heavy) areas of Newton:
(1938 "residential security" map
, widely used for redlining.) Looking at the two halves of the map, it's easy to see exactly why the area's highway system (including the unbuilt highways) was designed as it was.
Incidentally, Fred Salvucci has talked about his immigrant grandmother was displaced - rudely, and underpaid for her house - for the construction of the Pike through Brighton. That led him to question what he was being told to do with the Inner Belt, which resulted in him joining the coalition to oppose it.