Trancas Bridge Project Update: The Good, The Bad, The Ugly

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Scoping plans for the new Trancas bridge, expected to be completed by 2023. 

Caltrans’ Trancas bridge replacement project, fully funded at a cost of $10 million, will finally begin construction in the summer of 2020. It has been slowly clearing one hurdle after another. 

After holding public meetings in the Trancas area in 2016, its environmental impact report was approved a little more than a year ago, in June 2017. The bridge replacement project is now in its design phase, with construction scheduled for 2020 to 2023. That is a two-year delay from the original construction estimate, which had the project set to begin in June 2018.

During the construction, Caltrans plans to keep all four lanes of traffic open on PCH, and to keep a bike and pedestrian lane open on one side—with the ocean side first. Caltrans Public Information Officer Michael Comeaux said they determined that there was enough extra space available to do that.

“On the inland side of the bridge, a significant amount of dirt needs to be removed and the creek bed has to be widened so it doesn’t block water from going under the bridge,” Comeaux said.

Comeaux told The Malibu Times that even though the construction phase is three years long, the bridge will be fully open after the first 18 months. The last 18 months will consist largely of replanting vegetation and other work that “will take place largely off the roadway.”

Built in 1927, the 91-year-old bridge on Pacific Coast Highway that crosses Trancas Creek (just east of Trancas Country Market) is in dire need of replacement. A couple of years ago at a local scoping meeting, Caltrans Senior Environmental Planner Karl Price said the bridge had only been designed for a 50-year lifespan, meaning it should have been replaced back in 1977. He said the bridge was widened in 1938, and experienced “scour and erosion problems” from 1967 to 1998 that were repaired at various times with riprap, regrading and stabilization of the dikes.

“It’s an old bridge with a history of scour problems and several nonstandard features,” Shahriar Yadegari, transportation engineer, said at that time. “We want to replace this bridge with a safer bridge that meets current design standards. As of now, the railings don’t meet safety standards and the design does not meet earthquake standards … A new bridge will also be structurally sound, have room for a bike path, a 75-year lifespan, better aesthetics and less impact on creek flow.”

A couple of different new bridge options were presented to the public—a “short” bridge option and a “long” bridge option. In the end, Caltrans went with the “long” option, which was also favored by the California Coastal Commission. The new bridge will accommodate a wider creek flow, making it more environmentally friendly.

While the current bridge is 85 feet wide and 90 feet long, the new bridge will be 108 feet wide and 240 feet long. Comeaux explained that the LA County Flood Control District did run-off calculations that included how much space would be needed under the bridge in the event of a wildfire that would cause fire debris to wash downstream. They determined that four bays or 60-foot spans would be needed to accommodate debris flow.  

In January 2016, prior to a public scoping meeting, Matt Holm, a Caltrans structural engineer, performed a visual inspection under the bridge. 

“I could literally break concrete off with my bare hands when I looked at the bridge today,” Holm explained at the time. “The rebar is rusted and exposed, and one of the columns [holding up the bridge] has split. The other three columns are doing all the work. It’s time to get this thing replaced.”

Knowing the bridge is in such bad shape, some neighbors have asked whether the bridge could withstand the 44,000 dump-truck loads full of sand that would be crossing it if the Broad Beach sand replenishment project gets underway sometime in the next two years (assuming the trucks would be coming down PCH from the north and then turning into a staging area at the end of the Zuma Beach parking lot).

“Caltrans regularly inspects bridges for safety, including truckloads,” Comeaux said. “If there’s any indication that the bridge can’t handle the maximum legal truck weights, Caltrans will notify truck operators of reduced weight limits. It’s something they’re prepared to do at the first indication of need.”