SAN FRANCISCO (CBS SF) — Caltrans crews made good use of the empty roads and reduced traffic due to the coronavirus shelter order over the weekend, making progress on the new US Highway 101 bridge deck in San Francisco.

The new northbound 101 deck at Alemany Circle just before the Interstate 280 merge will soon be ready for traffic, but major detours remain in place and Caltrans is warning drivers to slow down.

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The construction, detours and northbound 101 closure into San Francisco started Friday.

During any ordinary Monday morning commute, it would be carmageddon. Usually, over 240,000 vehicles travel through the corridor on a daily basis. But with only essential workers on the road, traffic is way down.

“With 40 to 60 percent reduction, we’re able to come in and close off the freeway and be very efficient about the way we’ve done this work,” said Caltrans spokesperson Bart Ney.

The project to replace and seismically retrofit the bridge deck was moved up from July to late April to take advantage of the stay-at-home order. 

“It’s hard to say anything there’s been anything good about the lockdown. What has been good is people have been obeying it,” said Ney. “And this project is an absolutely silver lining in that.”

Demolition crews have been working 24/7 to break up the 70-year-old section since the project began Friday. Right next to them, crews are doing the framing work. Concrete will get poured in soon after debris is cleared.

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To have all three crews working simultaneously, side by side, is unusual. It’s more costly, but saves time.

“There’s certainly a sense of urgency and a sense of safety as we’re moving forward with this,” explained Ney. “We want this whole project, not every bit of it, but the parts that are impactful, done before people come back to work.”

One issue with less crowded freeways during the shelter order has been speeding drivers. CHP have recorded a marked increase in the  number of speeding tickets given out to drivers going over 100 MPH.

The fast drivers are also endangering the lives of Caltrans construction crews. Caltrans has issued an urgent reminder to slow down to 35 miles an hour in construction zones.

The project should be done by the May 3 target date and possibly even sooner.

A project of this magnitude normally would have taken about 18 days. Caltrans crews to complete the undertaking in about half that time.

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Caltrans has additional information about the project available on its website. There are also multiple live web cameras showing the demolition and construction as it happens.