The California Highway Patrol has reopened U.S. 101 in San Mateo this morning after downed lines prompted full closures of north and southbound lanes for more than an hour.

Officers responded to the area after receiving reports of downed lines covering various lanes of U.S. 101 near E. Hillsdale Boulevard just before 5 a.m., CHP Officer Nicole Pacheco said.

PG&E workers who responded to the scene determined that the fallen cables were phone lines, not high voltage power lines, utility spokesman J.D. Guidi said.

The CHP diverted traffic off of the highway at various off-ramps while the hazard was investigated. A Sig-alert that was issued at 5:11 a.m. was canceled at around 6:30 a.m.

Traffic in the area remained heavily backed up as of 6:45 a.m.

— Bay City News Service

Are you receiving Express, our free daily e-mail edition? See a sample and sign-up for Express.