Growing up in Westwood in the late 1960s to 1970s, our family drove through Dedham Square a lot to shop at the then new, Dedham Mall as well as go to my grandparents' house in Milton just past Readville so I have something of a memory of this area.
By circa 1968, I can recall an old, brick factory/warehouse building along Rt. 1 northbound possibly where Petco is today, just south of Mah Way (or maybe it was just north of Mah Way, where the small shopping plaza with Benjamin Moore is.) It had a rail siding in front of it with a rail loading dock parallel to Rt. 1. We used to come up Rt. 1 north to Mah Way (never knew the name of this road) then on to Eastern Ave. and we used to bump over the tracks turning onto Mah Way. I am quite sure in my first years there (66 to 69) there was occasionally a box car sitting in front of that building. For some years the tracks ran north through the parking lot of what appears now to be a Benjamin Moore store. In Streetview, https://firstname.lastname@example.org ... authuser=0
one can still see a hint of the rails, which must have been buried. The orphaned rails ran prominently through that parking lot for years and years before disappearing at some point.
In 1992 I recall seeing some rail ends sticking out of the landscaping in front of the Papa Gino's a bit further south along Rt. 1 Those would be remnants of the rail that once ran south to Islington before Rt. 1 was built which the earlier-mentioned siding aligned with.
The area where the soccer field is was a tired rail road yard area for years through at least the 1970s and maybe into the early 80s. I can recall a high level rail freight platform in there beyond the RK building (once Child World.) I also recall some abandoned barrels or something on that wooden platform. There may have even been a few box cars or other freight cars sitting nearby there for some time too back then, but cannot be sure.
I do recall, as we drove up Whiting Ave, there were old businesses backing up to the rail line running to Readville, including a very sketchy (to my 8 year old eyes) "Metropolitan Coal Company" coal depot, with several open coal bins along an unpaved, very weedy truck parking lot. (Circa 404 Whiting Ave.) After that, we'd turn north onto River St. and pass under the iron RR bridge that for years bore the last livery of the New Haven Railroad. That bridge slowly rusted, but did manage to last until maybe 20 years ago (a very rough guess as I wasn't passing through there much by then.)
At the time, of course I had no idea what history was slowly fading away before my eyes even though the construction of Rt. 1 through Dedham had already done a lot of damage.
Looking at the traffic paralysis that Dedham routinely puts up with from Rt. 128 to West Roxbury, nowadays I wonder if people still consider the construction of Rt. 1 in what I think was the late 1930s to be worth it. The town center was just about wiped out as it once was.