Finished a year ahead of schedule, the Detroit-Windsor Tunnel cost a total of $23 million. President Herbert Hoover formally dedicated the tunnel on November 1, 1930, by turning a key in Washington that rang bells in Detroit and Windsor. There was a decline in traffic through the tunnel in the 1930s due to the effect of the Great Depression on the industrial city of Detroit. However, once the Detroit River ferry service closed in the 1940s, tunnel traffic began to increase. Jointly owned by the cities of Windsor, Ontario, and Detroit, Michigan, the Detroit-Windsor tunnel is the only existing underwater international vehicular border crossing. The tunnel is ventilated by fresh air pumped in at 1.5 million cubic feet per minute.
A twin-tube passageway that offers freight trains the shortest rail route between Chicago and the east coast, the Detroit River Tunnel has been transporting goods between the United States and Canada for over 100 years and was used heavily during the 1940s. The first train went through the tunnel on July 26, 1910, and the first freight train passed through on September 17 of that year. The tunnel cut the time it took to cross the Detroit River by train down from days to about 12 minutes.
The Detroit River was a high-traffic area for smuggling alcohol during the Prohibition era that began in 1920 and ended in the early 1930s. Barely one mile across in some places, it was fairly easy for cargo to be smuggled under boats and through old underground tunnels. When the river was frozen in the winter, smugglers drove across the ice from the United States to Canada. The waterways were heavily patrolled by state and government agencies, but in spite of their efforts, over 75 percent of illegal liquor entered the United States across the Detroit River, Lake St. Clair and the St. Clair River. These tunnels were later used in the 1940s by undocumented workers who crossed the border and then hid in abandoned buildings near the Port of Detroit.
In the early 1930s, several exploratory subway pilot tunnels were built. The Great Depression ended funding for the project and the subway was never completed. Some of these tunnels were used in the 1940s as utility corridors for pipes and electrical cables.
