Traffic on eastbound Interstate 80 is open again at Castle Peak Road in Nevada County, say Caltrans officials after a big rig wreck closed the stretch just after noon.

Authorities at 3:15 p.m. lifted a SIG alert that had been in place since 1 p.m., according to information on the California Highway Patrol’s website. Earlier, frustrated motorists were reported by CHP turning around at the site and driving along shoulders and the center divide to avoid the stalled traffic.

According to to the CHP, a tractor-trailer went off the interstate and down an embankment just after noon Saturday near Castle Peak Road. The wreck backed up eastbound I-80 traffic for hours before the road reopened.