Queen Street's busiest stretch through downtown Toronto is officially closed-off to vehicles as of Monday morning, priming the area for traffic headaches planned to last for the next four and a half years.

Queen Street between Victoria and Bay streets was closed off at midnight Monday morning until at least 2027 to accommodate construction work on the Ontario Line's Queen Station, and it didn't take long for heavy construction vehicles and warning signs to take over the busy thoroughfare.

Orange fencing blocks off the street at major intersections bearing Ontario Line signage reading "Your Tax Dollars At Work." Traffic still flows on intersecting streets like Bay, creating individually-partitioned blocks of Queen Street construction.

Much of the first-day construction work appears to involve crews setting up dividers and wayfinding to keep traffic and pedestrians flowing around the closures.

Pedestrians can make use of new wayfinding signage fixed to construction fences to navigate the confusing closures.

Other signs assure passersby that the businesses obscured by fences and heavy equipment remain open during the closure. Similar signage was installed near Eglinton Avenue storefronts during the construction of the Crosstown LRT, however, many businesses along that stretch have not survived the long-term disruption to foot traffic.

The closures have forced diversions on the 501 Queen streetcar route, with vehicles diverting both ways between McCaul St. and Broadview Ave. via Dundas St. as of 12:01 a.m.

Streetcars are following a temporary diversion along Dundas Street West, parallel to the main route.

This temporary route will eventually be replaced by a long-term diversion route running westbound along Richmond St. and eastbound along Adelaide St. for the duration of construction.

Closure of the roadway frees up space for construction crews to undertake work on the new subway station connection without disturbing the existing infrastructure, including the TTC's Line 1 and its existing Queen subway station.

Metrolinx estimates this inconvenience to drivers will cut approximately one year off the project timeline versus the temporary rolling road closures that would have otherwise been employed.