I guess this is actually a case of accidental preservation. Over the past 20 or so years, while working at and around Boston University I'd noticed this curved rail/flangeway sticking out of the ground on Babcock St. It headed in the direction of BU's Nickerson Field...formally "Brave's Field," but abruptly ended going into an alley. Then a couple of months ago I came across this aerial view and it all suddenly came clear.

You can see the streetcars to the upper left, behind the grandstand, near the ornate clay-tile roofed Braves ticket office (which stands preserved today as campus police headquarters). And, at the top right, possibly a Type 5 coming down Babcock street heading for the ballpark. The yellow arrow shows the location of the remaining traces of the trackage.

Probably only a matter of time before they dig this up and resurface the road. Amazing it has lasted this long.

Thanks for reviving some 60 year old memories. I lived on Babcock St., about 3 blocks south of Commonwealth Ave. in the late 1940s and early 1950s.

Those are not type 5's in the aerial views. They are 6000 series center entrance MU cars, the usual equipment for Braves Field specials at the time. A 3 car train is parked by the ticket office and the car you mentioned is probably the first car of another 3 car train about to make the turn. Notice that the ends of the deck roof are visible on each of the cars and that they are close to the end of the car, which means that it is a center entrance car, not a type 4, the other class of non-PCC cars used on Commonwealth Ave. at the time. Enough API lecturing.

There are many such places in some cities--Baltimore, Philadelphia, D.C., etc.--where one can find similar traces.

The Baltimore Streetcar Museum, for decades, used to have an "arrangement" whereas sections of girder rail that had been pulled out of Baltimore streets by city crews during repairs would be "dumped" at the BSM for future reuse. I'm told that rail sections pulled out recently have proven to be generally too brittle for reuse after fifty years or more under pavement. But the loops at each end of the BSM's demonstration track are former loops that came out from Baltimore streets.