It's the first day back after the long weekend but the third after a change of vehicles along the TTC's 5o5 Dundas and 506 Carlton routes where buses have replaced the familiar streetcars.

The changes went into effect on Sunday after signs were posted at stops along the routes outlining the change of service, which will witness a surge in bus traffic across two of the city's busiest east/west thoroughfares.

#TTC 506 Carlton & 505 Dundas routes are operating with buses due to streetcar shortage. @TTChelps is also coordinating to take advantage and conduct maintenance & track work along routes during this period. 506 route will divert to High Park Station. #Ward18 pic.twitter.com/rnk51E3SPJ

— Ana Bailao (@anabailaoTO) February 20, 2018

The change is primarily the result of the streetcar shortage the TTC has been facing with Bombardier behind on new vehicle deliveries and a significant chunk of the existing fleet requiring extensive maintenance on account of harsh winter weather.

Only buses running on the 506 Carlton/College route from today onward...because Toronto has run out of operational streetcars. Ain't that grand? #TTC #WorldClassCity

— FuzzyWuzzy (@FuzzyWuzzyTO) February 18, 2018

The change is expected to continue until late 2018 when the new streetcar inventory has increased and various maintenance projects wrap up along the routes.