RICHMOND (CBS SF) — Drivers on the westbound upper deck of the Richmond-San Rafael bridge will see sparks flying for several months as highway work crews replace dozens of expansion joints, one of which failed last month and dropped concrete on top of vehicles below.

Caltrans work crews are using jackhammers and blowtorches along with heavy equipment to demolish the existing joints and replace them with new ones.

READ MORE: UPDATE: Fremont Sexual Assault Suspect Now Charged in 3rd Case; Additional Victims Sought

On February 7, an expansion joint broke apart on the upper deck, sending chunks of concrete down onto cars on the lower deck of the bridge. Luckily nobody was hurt, but it caused a major traffic jam for the better part of a day, diverting commuters through wine country.

READ MORE: A Surprise Hit, Filipino-Theme Home Movie Filmed in Daly City Spawns Sequel

Only one joint was broken, and they fixed it. Then Caltrans engineers found dozens more had some wear and tear. So now they have decided to replace all the joints that date back to the 1950s.

“As a precaution, there’s about 62, 63 of these on the bridge that we decided as a risk assessment, we’re going to replace these joints now,” said Tony Tavares, CALTRANS District 4 Director.

MORE NEWS: COVID Reopening: East Bay Moviegoers Carefully Step Back Into Theaters

While the work is taking place, the Richmond-San Rafael bridge will be closed form 9 p.m. to 5 p.m. every night. Tavares said the project should take about three months. Later this year, Caltrans will begin a similar 3 month project to replace the joints on the lower deck.