The road diverges from Dougall Avenue south of Downtown Windsor, travelling northward over the Essex Terminal Railway/CP Rail tracks, before terminating at a turnaround and parking lot at Dieppe Gardens in Windsor's core.
Its purpose is to divert traffic from the Ambassador Bridge (via Highway 3/Huron Church Road), by sending it to the Tunnel (Via Dougall Parkway, Dougall Avenue, to the Detroit-Windsor Tunnel, along Wyandotte Street to its Canadian terminus at Goyeau Street.
Traffic onward into the United States generally continues onto Woodward Avenue, Detroit's "Main Street", which lies along the same alignment as Ouellette.
[1] The road is quite busy and is used mostly by cars, as trucks longer than 45 feet cannot fit around the curve on the American side of the Detroit Tunnel, and the Ambassador Bridge tends to be clogged.
Four years later, it was designated as a Connecting Link, enabling Windsor to receive monetary and mechanical/paving assistance in maintaining the road, and to continue to sign it as Highway 3B, should it be downloaded.