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.

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.

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.

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