Detroit Free Press International Half-Marathon

This cross-border half is the signature shorter race of Detroit Free Press Marathon weekend. Runners leave the United States, enter Canada, and return underground, making entry documentation and border eligibility as important as ordinary race preparation.

The route crosses into Windsor on the Ambassador Bridge and returns through the Detroit-Windsor Tunnel before moving through downtown and Midtown Detroit to Campus Martius. The bridge climb, tunnel descent and rise, and wave traffic make effort-based pacing more useful than treating it as flat.

October in Detroit can range from crisp and still to cold, wet, and windy. Conditions on the bridge may differ sharply from street level, while the tunnel briefly feels warmer and more humid.