PORT HURON, Mich. -- State officials in Michigan say extended construction of inspection booths at the Blue Water Bridge has been delaying Canada-bound traffic at the border crossing.

The bridge between Port Huron in Michigan and Sarnia in Ontario spans the St. Clair River, which forms part of the U.S. border with Canada.

The Times Herald newspaper reports Tuesday that work on the six booths has delayed traffic by at least an hour at times.

A Canadian government website that monitors the crossing indicated there was a 15-minute delay of U.S.-bound traffic on Wednesday morning.

The work on the inspection booths was supposed to be completed by June 30 but won't be done until mid-September.

Michigan Department of Transportation Department senior project engineer Meghan Vohs says one of the issues has been steel and other material not meeting state specifications.