Canada’s busiest trade corridor has quietly moved north.
High tolls at the Ambassador Bridge have driven record commercial traffic through the Blue Water Bridge, allowing the Sarnia, Ont., crossing to overtake Windsor as the busiest commercial crossing on the Canada-U.S. border for the first time in decades.
“The Blue Water Bridge has surpassed all other international crossings in commercial traffic volume,” Alexandre Gauthier, the communications manager for the Federal Bridge Corporation Limited (FBCL) said in an email to CBC News.
FBCL is a Crown Corporation that owns and operates certain border crossings, including the Blue Water Bridge.
For every month in 2025, the Blue Water Bridge surpassed the Ambassador Bridge, with about 2.1 million commercial truck trips at Sarnia that year compared to roughly 1.9 million at Windsor, according to data from the Bridge and Tunnel Operators Association.
The trend has continued into 2026. In the first three months of the year, the Ambassador Bridge saw 496,796 commercial truck trips, compared with 531,732 at the Blue Water Bridge.
Tolls for commercial trucks at the Ambassador Bridge are the highest in the region — up to $27 per axle — almost four times the $7 per axle at Blue Water Bridge and the proposed $12 an axle rate for Gordie Howe, when it finally opens.
The toll gap has effectively redirected continental supply chains north to Sarnia, reshaping one of North America’s busiest trade corridors and arriving as another complication for the Gordie Howe bridge, already late and over budget.
“Price sensitivity entered in the market for the supply chain,” Stephen Laskowski, the President and CEO of the Canadian Trucking Alliance and the Ontario Trucking Association told CBC News.
Laskowski said the result is a rare moment of distortion at one of North America’s most critical trade chokepoints.
“Historically over the decades, the Ambassador Bridge was always the leading crossing between Michigan and Ontario by a significant number,” he said.
“It goes to show you the price sensitivity of tolls and the tremendous value of the Gordie Howe Bridge to the supply chain.”
There is still no firm open date for the Gordie Howe International Bridge — meant to modernize and decongest the Windsor-Detroit corridor — the opening of which has been delayed twice and is still politically and administratively uncertain. Last month, the company said it would open “this spring.”
Those delays are not trivial: one recent American analysis estimated losses of up to $7 million US per week tied to a postponed launch.
The mega-project, hailed as a “once-in-generation undertaking,” is also about $700 million over its $5.4 billion budget, pushing the cost to roughly $6.1 billion, despite early federal assurances back in 2015 that the public-private-partnership, or P3 model, would keep it “on time and on budget.”
“Politicians loved it,” Matti Siemiatycki, a professor of geography and urban planning at the University of Toronto whose work focuses on large-scale infrastructure projects said of the P3 model. “They clung to this idea of ‘on time and on budget’ like a life raft.”
The P3 became the dominant way governments across Canada tried to build infrastructure for a decade between the early 2000s and the early 2010s, but they eventually fell out of favour, Semiatycki said, because the promise of “on time and on budget” didn’t consistently hold.
They’ve recently seen a resurgence, Semiatycki said, especially when it comes to major transit project, but recently, as they did more than a decade ago, “the P3 has proven to be adverserial.”
Instead of working together, he said, the private and public sector end up fighting over who pays, in the end, governments still end up paying when things go wrong.
“There’s transferring risk on paper, but in practice you have to wonder who’s responsible for these risks,” he said. He noted some risks can’t actually be shifted, such as the COVID-19 pandemic and threats from U.S. President Donald Trump — so when they hit, governments must step in to keep the project moving.
“No one takes on risk for free,” he said. “The companies will charge a premium for that risk and what we’re seeing is that when risks materialize, oftentimes governments still end up stepping in and paying.”
CBC News asked Infrastructure Canada and the Windsor-Detroit Bridge Authority, the consortium responsible for the Gordie Howe International Bridge about the project’s delays, rising costs and how risk is being shared but did not receive a response by deadline.
The Ambassador Bridge was also asked about rising tolls and shifting traffic patterns but did not respond.
