SAN RAFAEL (CBS SF) — CHP and Caltrans have reopened all lanes on the Richmond-San Rafael Bridge Thursday after authorities were forced to close the span multiple times due to falling concrete from the upper deck.

All lanes reopened at 8:17 p.m., according to the CHP.

Caltrans made a temporary fix by installing large metal plates so the bridge could reopen.

Vince Jacala, a Caltrans spokesman, told KPIX “The metal plates are a short-term repair so … that we can open the bridge now so that we can have it ready for the morning commute and the late night commute. And then, over the weekend, we are going to assess it some more so that we can figure out the longterm plan for the fix.”

The falling concrete damaged a vehicle and created a traffic nightmare for Bay Area drivers

CHP and Caltrans decided to close the bridge in both directions at about 4 p.m. after additional concrete in the same area where the problem first arose was loosened by traffic on the bridge, falling down to the lower deck.

An emergency order was issued to get a contractor to make permanent repairs this weekend, according to a Caltrans press release issued Thursday evening.

The traffic problems started after a Sig Alert was issued at 11:20 a.m. Thursday morning when authorities closed the bridge in the eastbound direction due to a report of falling concrete. A CHP spokesperson said that golf ball size or larger chunks of concrete were reported falling from the underside of the span’s upper deck.

CHP Officer Andrew Barclay said at least one car had been hit by the falling concrete, causing ‘major damage.’

“The initial report came from a caller who reported their car had been hit by concrete,” he said. “We asked them to stop so we could get a report, but they said they were on their way to the airport.”

Video from Chopper 5 showed CHP and Caltrans personnel inspecting an area of the bridge at about mid-span. There are vehicles stopped on the bridge behind where CHP have halted traffic.

At about 11:45 a.m., the CHP Marin Facebook page posted images of sizable chunks of concrete that had fallen from the upper deck as well as a cracked hole in the upper deck above.

Authorities shut down the westbound portion of the bridge that carries at least 80,000 vehicles a day at about 12:08 p.m.

Vehicles that were on the lower deck of the span when the closure happened were being turned around to exit the bridge, as were cars and trucks that were lined up to enter the bridge.

At about 12:20 p.m., CHP officers let some of the vehicles already on the bridge through the area where the concrete was falling. However, authorities said they were not going to allow any of the cars waiting to get onto the bridge across.

“Obviously, we understand the people who were initially stuck behind the closure have been there for a while. Our concern is getting them off the bridge but obviously we need to do that safely,” Barclay said. “That involved us making sure that no more concrete would be falling as they are trying to get across. That’s not an opening, that’s just us leading that traffic off.”

Barclay said that after the initial concrete chunks were found, more pieces were still falling from the upper deck, dislodged by the westbound traffic.

“We had to closed the top deck because all the traffic coming across bounces that deck up and down, causing the concrete to fall,” said Barclay. “We need to get the lower traffic across and we can re-evalute from there as well as looking at the top deck to see if any concrete is actually falling. Our sergeant found those [the pieces that had fallen] when he arrived and there was actually concrete still falling onto the bridge.”

Caltrans inspectors don’t know what caused the concrete to break loose. They said contractors have been working on the upper deck to build a pedestrian and bike lane.

They don’t know if that activity created more vibration to loosen the concrete or if that’s even connected to the problem.

Authorities were able to reopen a single lane in the eastbound direction shortly after 3 p.m., but the reopening of those lanes only lasted about an hour.

The closure created traffic chaos on the span and on both sides of the bay as drivers tried to get around the closure. The approaches to the Golden Gate Bridge and the Bay Bridge getting out of San Francisco were congested by early afternoon, while eastbound traffic on the San Mateo Bridge was slow going across the entire span.

The traffic began back up from Highway 37 onto 101 north before 3 p.m. as hundreds of cars tried to get around the Richmond-San Rafael Bridge closure.

In San Francisco, traffic downtown had slowed to a crawl due to the heavy traffic headed to the Bay Bridge.

The SFMTA shut down the California Street cable car line due to heavy traffic conditions and later stopped service on all cable car lines for a time.