An accident has closed northbound I-15 at Rancho Bernardo Road according to the California Highway Patrol.
The collision was first reported at 10:30 a.m. and involved a semi tractor trailer that had rolled over onto its roof according to preliminary reports.
The CHP opened the express lanes to all traffic. Cars moved forward through the side shoulder emergency lane for hours.
The northbound lanes were reopened to traffic, approximately 4 hours after the initial closure.