HERCULES (CBS SF) — Lanes of westbound I-80 in Hercules have reopened hours after Contra Costa fire units knocked down a big-rig fire on the freeway off-ramp, according to authorities.

The report of the fire first surfaced at 2:49 p.m. when a big-rig car hauler was spotted on fire at the Hercules off-ramp east of State Highway 4. The response to the fire is blocking the right lanes of westbound I-80.

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The big-rig fire spread to the hillside by the off-ramp, but had not spread to the vehicles the car hauler was transporting yet, according to reports.

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CHP has issued a severe traffic alert due to the fire.

As of about 3:15 p.m., crews had knocked down the fire on the truck and hillside, but responding units were still blocking westbound lanes of I-80 as firefighters mopped up.

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Clean up continued until shortly before 6 p.m., when all lanes were reopened.