For almost 100 years, various hazmat categories were constrained at this I-75 point of entry at the Detroit and Windsor port of entry (POE). When open, the Howe Bridge will remove most if not all hazmat restrictions.  (See 9 Classes of Hazardous Materials from the Federal Motor Carrier Safety Administration.) Sometime by fall of 2025, the Gordie Howe International Bridge will open between the US (entering I-75) and Canada (entering Highway 401) at that POE. Already the single busiest POE between the two countries, the Howe Bridge is being promoted as a “legacy Infrastructure project.”
Highway 401 is the busiest highway in all North America. I-75 is no slacker and spans six states, from Sault Ste. Marie, MI, to Miami, FL, cutting through many population centers in its path. Even absent the environmental concerns of highways themselves—concerns felt across the country where highway expansion is being actively opposed—there is particular concern to the Howe Bridge and its granddaddy, the Ambassador Bridge just two miles away. That is: trade in hazmat. Current data is elusive, but in 2012, the Michigan Department of Transportation reported “Close to a million shipments of hazardous materials traverse the United States daily,” and “roughly 95 percent of U.S. hazmat shipments are transported by trucks on highways and roads.” (Citations: National Research Council and Federal Motor Carrier Safety Administration.)

Without any doubt, the two countries have only increased production of hazardous materials. When constraints are lifted, rapid trade increases of heretofore restricted substances will be trucked between Miami and Quebec and beyond.
The Howe Bridge, and now likely the Ambassador Bridge (“we are not going anywhere”) will have massive amounts of hazmat trade. The trucking industry is salivating for the increase of all types of international trade between the two countries. What and how much predicted hazmat right now is either anyone’s guess or a closely guarded secret. Ohioans learned a painful lesson from the February 2023 hazmat train derailment in
East Palestine, Ohio. As Move To Amend already knows: Corporations skirt regulatory controls and hazmat is no different. Although his report is mostly about railway industry safety—or lack thereof in a stunning absence of regulatory controls—a chilling report by ProPublica reporter Topher Sanders from earlier this year reveals that. Sander’s report should have everyone concerned about what is passing through our towns, day in and day out, in rail car AND in trucks on highways. (This Fresh Air interview with Sanders is compelling.