If you plan to cross the border this weekend, you might want to either make the trip on Saturday or hold off a few hours on Sunday.
The Detroit Free Press Marathon will close the Windsor Detroit Tunnel between 6:15 a.m. and 10:15 a.m. on Sunday as thousands of marathon runners participate in the annual event.
The Ambassador Bridge will stay open, but traffic will be limited.
The marathon starts at 7 a.m. at Fort Street between Second and Third Avenues in Detroit, head over the Ambassador Bridge, along Windsor's riverfront, and back over the border through the Windsor Detroit Tunnel.
The race through Windsor streets means some roads will close at 6 a.m. They include Huron Church Road between the Ambassador Bridge and Riverside Drive, Riverside Drive from Huron Church Road to Goyeau, Goyeau between Riverside Drive and Park Street, and Park between Goyeau and Ouellette Avenue. They'll reopen at 10:15 a.m.
An updated course includes the Woodbridge neighbourhood, the District Detroit, Eastern Market, and the Dequindre Cut.

The race ends at Woodward Avenue and Congress Street at the Michigan Soldiers' and Sailors' Monument.
The International Half Marathon, Marathon Relay, and U.S. Half Marathon also start at 7 a.m. on Sunday.
There are events on Saturday, including the Kids Marathon Final Mile, the Competitive Mile, and the 5K.
Ryan Corby of Novi, Michigan, won last year's marathon with a time of 2:24:28. The first Canadian to cross the finish line was Jeramie Carbonaro of LaSalle, who did it in 2:45:16.