A single-vehicle rollover crash snarled westbound rush hour traffic on Interstate 80 near the mouth of Parleys Canyon for about two hours Friday, police said.

About 4 p.m., a Ford Focus passed another car near milepost 130 and the driver lost control in slick conditions, said Utah Highway Patrol Sgt. Jeff Plank. The car hit a cement barrier and rolled several times, critically injuring one person and seriously injuring another.

The two were taken to University Hospital, one by medical helicopter and the other by ground ambulance, Plank said.

The crash caused a large traffic backup, and anyone traveling from Park City to Salt Lake City or areas farther west was advised to use an alternate route. Crews cleared the crash about 6 p.m., the Utah Department of Transportation reported.