Traffic was halted and backed up for a couple of hours last evening after a semi truck  jackknifed near the Lapeer Road overpass on Interstate 94/69 in Port Huron Township. Reports from Port Huron Township Fire Department state that no other vehicles were involved.  The accident occurred at approximately 7:45, and according to the department, a fuel leak was part of the reason, for the tie-up in traffic.  Along with  the Port Huron Township Fire Department, the St. Clair County Sheriff and St. Clair County Hazardous Operations  responded to the scene.