Cross-Border Trade Between Ontario and the Great Lakes States: 2026 Economic Analysis

Cross-border trade between Ontario and the Great Lakes states of Michigan, Ohio, New York, and Pennsylvania represents one of the most significant bilateral trading relationships in the world. Statistics Canada data shows that Ontario’s merchandise trade with these four states alone exceeded 340 billion dollars in 2024, sustained by integrated supply chains in automotive manufacturing, agriculture, natural resources, and advanced technology.

Trade Volume and Key Corridors

The Windsor-Detroit corridor is the single busiest international trade crossing in North America. The Ambassador Bridge and the Detroit-Windsor Tunnel together handle approximately 30 percent of all Canada-U.S. merchandise trade by value. The opening of the Gordie Howe International Bridge in June 2025, the first new crossing between the two cities in over 80 years, has added significant capacity to this critical corridor.

Transport Canada data shows that the Gordie Howe Bridge handled approximately 4,200 commercial vehicles per day in its first six months of operation, diverting traffic from the congested Ambassador Bridge and improving crossing times during peak hours. The bridge’s direct highway-to-highway connection between Ontario’s Highway 401 and Michigan’s Interstate 75 has been particularly valued by just-in-time automotive supply chains that cannot absorb unpredictable border delays.

The Niagara Falls crossings, including the Lewiston-Queenston Bridge and the Peace Bridge at Fort Erie-Buffalo, handle the second largest volume of Canada-U.S. trade in the Great Lakes region. The Buffalo-Niagara corridor facilitates significant trade in agricultural products, manufactured goods, and energy, with total cross-border goods valued at approximately 85 billion dollars annually.

Automotive Supply Chain Integration

The automotive sector exemplifies the deep economic integration across the Great Lakes border. A typical vehicle assembled in Ontario crosses the Canada-U.S. border multiple times during production as components move between plants in both countries. The Canadian Vehicle Manufacturers’ Association reports that Ontario’s automotive sector exported 62 billion dollars worth of vehicles and parts in 2024, with the vast majority destined for Great Lakes states.

Major assembly plants in Oshawa, Oakville, Brampton, and Windsor depend on daily shipments of components from suppliers in Michigan, Ohio, and other states. Similarly, U.S. assembly plants in Michigan and Ohio source substantial volumes of parts from Ontario suppliers. This integrated supply chain supports approximately 125,000 direct manufacturing jobs in Ontario and hundreds of thousands more in supporting industries.

The transition to electric vehicle production is reshaping these supply chains. Stellantis is investing 3.6 billion dollars to retool its Windsor Assembly Plant for EV production, while General Motors has committed 2 billion dollars to its Oshawa and St. Catharines facilities. The emerging EV battery supply chain, anchored by plants from LG Energy Solution in Windsor and Umicore in Loyalist Township near Kingston, is creating new cross-border trade flows in battery materials and components.

Agricultural Trade

Agricultural trade across the Great Lakes border benefits from complementary growing conditions and processing capacity on both sides. Ontario exports approximately 4.8 billion dollars in agri-food products to Great Lakes states annually, including greenhouse vegetables from the Leamington-Kingsville cluster (the largest greenhouse concentration in North America), livestock and meat products, and processed foods.

In the opposite direction, Ontario imports significant volumes of corn, soybeans, and specialty crops from Michigan and Ohio for use in food processing and animal feed. The integrated nature of Great Lakes agricultural trade means that disruptions at border crossings have immediate impacts on food supply chains and commodity prices in both countries.

Energy Trade

Energy flows across the Great Lakes border in both directions. The Enbridge Line 5 pipeline, which crosses the Straits of Mackinac between Lakes Michigan and Huron, carries approximately 540,000 barrels per day of light crude oil and natural gas liquids from western Canada to refineries in Sarnia, Ontario, and further east. This pipeline supplies approximately 55 percent of the crude oil processed by Ontario refineries and is a critical piece of energy infrastructure for the province.

Electricity trade across the Great Lakes border is managed through multiple interconnections between Ontario’s electricity grid, operated by the IESO, and grids in Michigan, New York, and Minnesota. Ontario is a net exporter of electricity to the United States, selling surplus nuclear, hydro, and wind generation that totaled approximately 20 terawatt-hours in 2025, generating over 2 billion dollars in export revenue.

Policy and Regulatory Considerations

The Canada-United States-Mexico Agreement (CUSMA), which replaced NAFTA in 2020, provides the trade framework that underpins Great Lakes economic integration. CUSMA’s rules of origin for automotive products require 75 percent regional value content for tariff-free treatment, up from 62.5 percent under NAFTA. This higher threshold has encouraged further investment in Great Lakes-region auto parts manufacturing.

Border processing efficiency remains a priority for businesses on both sides. The Canada Border Services Agency (CBSA) and U.S. Customs and Border Protection (CBP) operate trusted traveller and shipper programs, including NEXUS and the Customs-Trade Partnership Against Terrorism (C-TPAT), that provide expedited border processing for pre-approved participants. Enrollment in these programs has increased significantly since the Gordie Howe Bridge opening, which includes dedicated lanes for program participants.