WALNUT CREEK-- An accident that started a car fire on northbound Interstate 680 near the Rudgear Road offramp blocked all lanes of traffic for almost an hour, a California Highway Patrol dispatcher said.

All lanes were reported blocked about 2:15 p.m., a dispatcher said. The crash was reported clear from all lanes about 3 p.m., though traffic remains slow in both directions.

No injuries have been reported as of this time.