Metrolinx has quietly announced the start of service for its new elevated rail line, revealing that the first GO trains will zip along this dedicated guideway through Toronto starting on Monday, March 27, 2023.

The Davenport Diamond Guideway project is a key element in Metrolinx's GO Expansion program, bypassing one of the busiest rail intersections in North America and overcoming another hurdle in the transit agency's goal to provide two-way, all-day frequent service on the Barrie GO Line.

Despite its obvious importance to Metrolinx's broader goals in the region, the transit agency barely made a squeak about the guideway's impending opening. The news came in the form of a construction notice rather than an official press release.

Look forward to being on the first revenue service train! cc @AlexanderGlista @KORichardson @TORailwayMuseum @HealthyCityMaps @munir_anika @AMAwithAMA #DavenportDiamond https://t.co/YFQPGKz2QQ

— Chris Drew (@chrisjamesdrew) March 16, 2023

The transit agency advised customers that "over the weekend, crews will tie the new west main line track into the existing main line track at the north and south limits of the project," adding that "GO Trains will be running on the elevated guideway as of Monday, March 27, 2023."

Local residents living in proximity to the Metrolinx corridor, from 600 metres south of Bloor Street to 300 metres north of Davenport Road will still have to contend with some more construction noise in the final weeks of construction leading up to the guideway's opening.

Other inconveniences include single-lane closures on Wallace Avenue on March 25 to accommodate the removal of the level rail crossing just west of Lansdowne, which will no longer be needed following the guideway's completion.

During the switchover, trains on the Barrie line will be replaced by GO buses, operating Saturday, March 25, until the end of service on Sunday, March 26.

The Davenport Diamond Guideway has set itself apart from the Eglinton Crosstown LRT at every step of construction. The guideway is indeed a much smaller and less complicated project than the delay-plagued Crosstown, but its comparatively efficient construction and highly-visible engineering have impressed onlookers throughout the build.

Completion of the guideway doesn't quite mean the end of the project, as a future linear park running below the new infrastructure will soon link neighbourhoods that have long been disconnected by the at-grade rail corridor.