992 is on the Willis Avenue line, eastbound on 125th Street, having just passed beneath the Third Avenue elevated. The convertibles were indeed most characteristic of the TARS fleet; there were 495 of them, 200 straight sided and 295 curve sided.
The Willis Avenue line was motorized on August 5, 1941, which was the day the City converted the Willis and Third Avenue bridges across the Harlem River to one way operation.
Since the franchise agreement that TARS signed with the City in 1940 required the company to motorize all of its routes by 1960, it did not make sense for TARS to make the track changes necessary to continue operation using both bridges.
Caption data from Bill Armstrong; photo courtesy the Bill Volkmer collection