There was a time when the curve between the Queen Elizabeth Way and the Gardiner Expressway at the Humber River was rather tight. In 1973-74, while the highway structures were realigned, the Long Branch car continued to run through the site on a single track with signals.
Rather than overhead contactors common on single track street railway operations everywhere, the TTC opted for subway-type track circuits to control access. With a lot of water in the construction site, especially through winter, “track down” conditions showing the presence of a “ghost” car, were an ongoing problem. Nonetheless, through service continued over the single track, first on the old alignment, and then on the new one.
Special work for the crossovers was mined out of the street. One location was on Dufferin north of King and the other on Spadina south of King.
The Dufferin crossover had been used originally for a shuttle service to the CNE western gate that operated with double-end equipment. Later, this location was a point where the TTC snow plows reversed direction. Yes, there were official routes for the plows and sweepers when the TTC still had such cars. Ironically, after the work at Humber, the TTC re-installed the crossover on Dufferin even though by then the snow fighting fleet that used it had been retired.
The crossover from Spadina was last used in 1948 when double-ended streetcar operation on the Spadina streetcar route (along with the route itself) ended, and it had been buried in asphalt for years.
Access to the construction site was much more relaxed than today when, of course, the streetcar line would have been shut down and replaced by buses.
The photos with Peter Witt cars were all on charters. The Tour Tram never got this far west.
Steve Munro 
The railway underpass on the north side was never changed, was it?
Interesting to see relatively few ex-Birmingham PCCs. There are quite a few 4300s and MU 4400s, but no 4600 MUs of either class.
Steve: The 4600s operated out of Russell, and therefore were not assigned to the Long Branch route which was based at Roncesvalles.
LikeLike
I was born in 1981. While I recall a few times seeing traffic signals in Ontario with those green backplates instead of the yellow, though it’s been many years now. Were those something specific to Ontario Highways, like how Lake Shore was Highway 2?
Also was this bridge construction the one that created the infamous Humber Hump on the Gardiner over which you could get your car literally airborne even going at about only 100 kph?
LikeLike
Re: Humber Hump. That was further east along the Gardiner near Windemere, by the old Queensway Motel, famous for other humps and bumps…
LikeLike
I recall passing through the single track from Humber Loop to Lakeshore on a transit excursion with some friends. Being an east-ender, it was a lot to take in. For some strange reason, my vague recollection was that the underpass was only wide enough for a single track, but that was probably just me being overwhelmed by a whole lot of new sites.
As for the green backplate traffic signals, I certainly lost this memory, as this would have been something I normally would have recalled. Being a bit of a traffic sign/signal junkie, I always wondered why (back in the early 70s) traffic signals within Metro Toronto had yellow backplates, while those outside of Metro limits had green. That was the case in Markham and Pickering, and a few places we would pass through on summer vacations in the Kawarthas. Seeing a green backplate traffic light in Toronto is something that should have stuck in my mind, but somehow it didn’t.
Was there ever streetcar traffic control using a gate somewhere? For some reason I have a vague recollection of this, and though it was for the single-track at Humber.
Steve: There is a gate visible in three of the photos.
LikeLike
Ah yes! I see it now, and it is yellow/black, which is how I remember it.
Funny how I focused on the green backplate traffic lights and missed the gate when looking at the photos and did the opposite back then.
LikeLike