FRESNO, Calif. — The northbound 5 Freeway near the Grapevine was experiencing a major traffic backup Wednesday afternoon following a big rig crash.

The California Highway Patrol said the semitruck was carrying 15-foot metal poles when it lost its payload, spreading the poles across all lanes. Officers said the two far-right lanes, starting south of Grapevine Road, have reopened.

Crews were actively working to clean up the debris.

CalTrans said traffic was backed up over six miles and growing. Caltrans cameras near the scene of the crash showed traffic at a near-standstill.

The traffic nightmare comes one day before Thanksgiving, traditionally one of the busiest travel days of the year.

Drivers are advised to expect delays and to not weave their way through traffic.

Meanwhile, AAA predicts that 55.4 million people nationwide will travel at least 50 miles from home between Wednesday and Sunday, the third-highest forecast ever by the auto club. AAA says most of them — 49.1 million — will drive.

The Associated Press contributed to this report.