The route serves to connect Niagara Falls, St. Catharines, Grimsby and the Stoney Creek community in east Hamilton to trains on the Lakeshore West line at Burlington GO Station in Burlington for further travel eastward towards Toronto.
This route operates primarily on the Queen Elizabeth Way, or the QEW.
The 12 Niagara Falls-Toronto route connects the Niagara Falls Bus Terminal to Burlington GO Station, making stops at Stanley Avenue and Highway 420 in Niagara Falls, Fairview Mall in St. Catharines, Grimsby Park and Ride and Stoney Creek Park and Ride.
On December 7, 2013, bus services moved from Niagara Falls VIA Station to serve the adjacent Niagara Falls Bus Terminal.
Starting February 24, 2014, onboard "real-time bus service information" was first introduced on select route 12 and 16 trips, with a full roll out by summer 2014.