 Unlike the Toronto Street Railway's Yonge line, the Metropolitan line was a single track, side-of-road operation using double-ended horsecars.The northward expansion of the Yonge streetcar line is related to the history of the Metropolitan line.On September 1, 1890, the Metropolitan line was electrified, thus preceding the electification of the Yonge streetcar line on the south side of the CPR line.