A semi-truck rolled on the ramp from Stoney Trail to southbound Metis Trail early Saturday morning, closing both off ramps and the stretch between Stoney Trail and 128 Avenue N.E.
Police estimated they would be on scene for "several hours" as of 4:30 a.m.
By around 8 a.m., the truck appeared upright and ready to be towed, damaged along its driver's side. YYC Transportation had not confirmed whether the area was cleared.
What's closed
Both off ramps from Stoney Trail to Metis Trail.
The area between Stoney Trail and 128 Avenue N.E.
Check 511.alberta.ca or the YYC Transportation account before heading that way, since ramp closures lift without much notice once a tow is complete.
Why drivers should care beyond the closure
Ramp rollovers can clear quickly once the truck is upright, but they often leave behind a bigger traffic problem.
Tow crews still have to inspect the trailer, secure or transfer the load, clean up debris and check whether fuel or fluids spilled onto the ramp. Even after lanes reopen, traffic can stay slow while drivers merge around equipment or avoid the area.
For northeast Calgary drivers, this interchange matters because it feeds traffic toward the airport, CrossIron Mills, warehouse districts, Metis Trail and the communities north of McKnight Boulevard. A closure here doesn't just affect one ramp. It pushes vehicles onto nearby routes that are already busy on weekends.
Why this interchange
Stoney Trail and Metis Trail sits in Calgary's northeast, serving the airport lands and the communities north of McKnight.
Métis Trail is an expressway built to provide direct access to Deerfoot Trail, Stoney Trail and McKnight Boulevard, and it's currently under design and construction between 96 Avenue and Airport Trail and Stoney Trail N.E.
It's also not the first semi rollover at this interchange. In 2023, a multi-vehicle crash on eastbound Stoney Trail near the Metis Trail exit left a semi on its side across the road, closing the eastbound lanes until early afternoon.
The ramp curve is the recurring factor
Calgary has had a string of these, and the mechanism repeats.
In October 2024, a cattle liner carrying approximately 95 cattle rolled on the off-ramp from eastbound Stoney Trail S.E. to southbound Macleod Trail. Seventeen cows died. Police said the semi-trailer failed to negotiate a curve as it took the exit, and speed was investigated as a factor.
In April 2020, a semi rolled on westbound Stoney Trail N.W. near Symons Valley Road, sending one of three occupants to Foothills Medical Centre with a potentially life-altering injury. The Calgary Fire Department credited the high-tension cable divider for preventing the truck from rolling into oncoming traffic.
In January 2024, a gravel truck heading south on Stoney Trail lost control and crossed the median near 17 Avenue S.E., in a crash involving three semis and a pickup.
Last August 20, a rollover on westbound Stoney Trail S.E. seriously injured a man, with police saying alcohol was believed to be a factor.
Police have not indicated a cause in Saturday's rollover.
Why loaded trailers roll on ramps
Cars can take many ramp curves comfortably at speeds that become risky for a loaded semi.
A trailer carries its weight higher, and the load can shift mid-turn. That combination means a truck can reach its rollover threshold well before a driver feels anything is wrong.
Liquid and livestock loads are worse again, because the weight actively moves during the turn.
That's why ramp speeds posted for trucks are frequently lower than for cars, and why the same handful of curves generate repeat incidents.
Stoney Trail carries a lot of freight
The ring road is roughly 101 kilometres and forms part of the CANAMEX Corridor, connecting Calgary to Edmonton and to Interstate 15 in the United States via highways 2, 3 and 4.
Its final segment opened in December 2023, completing the loop. At its busiest point near Beddington Trail, the six-lane freeway carried nearly 79,000 vehicles a day in 2019.
It exists partly to keep truck traffic off Deerfoot Trail and 16 Avenue, which means a disproportionate share of what's on it is commercial.
What's still unknown
Whether anyone was injured. Neither police nor EMS have released information on injuries.
What caused the rollover, and whether speed was a factor.
What the truck was carrying.
Whether the ramps have reopened.
We will update this article as more information becomes available.
Sources
Calgary Police Service
YYC Transportation
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