By Devin Fehely

MILPITAS (KPIX) — A large sinkhole opened on the westbound lanes of the Montague Expressway Friday night, 30 feet wide and 20 feet deep.

Traffic engineers say a drainage pipe which runs under the road was likely at fault and they feared it could be Monday night or later before repairs are completed.

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Milpitas Sinkhole

Crews work to fill sinkhole on Montague Expressway in Milpitas. (CBS)

On Sunday, crews rushed to reopen the road ahead of schedule as lighter-than-expected weekend rain allowed them to get a jump on repairs.

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They hope to finish before the Monday morning commute to avoid what could be a traffic nightmare.

Cal Parks, who lives nearby, wished them well.

“I think [the commute] would be a disaster, especially if people didn’t know about it. I’m sure there’s going to be many people coming or attempting to come this way to work,” Parks said.

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There’s at least one, rather thin, silver lining: this sinkhole has only affected westbound lanes. The eastbound lanes have remained open during repairs.