By Camas Frank ~
Come 2017 there’s set to be a complicated traffic detour pattern around a certain spot on Marsh Street.
The average City of SLO motorist may not have noticed, but there’s a bridge between Osos St and Santa Rosa Avenue, dating back to 1909, with a driveway for DaVita San Luis Obispo Dialysis connecting directly to it. It’s one of several small bridges that crisscross the Downtown area without opulence. This one is even wider than it is long, according to engineers.
Since the City depreciates the monetary value of many of it’s infrastructure “assets” for 100 years, and the California Department of Transportation (Caltrans) is less concerned with age than it is condition, the bridge is right in the financial sweet spot for replacement.
During a public gathering at the SLO City/County Library on Palm St. on March 2, the City’s project manager, Mike McGuire said the Caltrans “score” for the bridge had dropped in recent years from an assessment in the 80s out of a 100-point scale to the 50s. However, its not grade school as 50 isn’t considered failing; bridges are only considered non-operable at 0. He also noted that generations of repairs to the bridge had kept that score up until now. Current reasons for wholesale replacement include exposed rebar, which is rusting through, both in plain sight in the guardrails above the roadway and out of view under the span.
Contributing to the damage was an accident several years ago in which a vehicle crashed through the concrete railing and a temporary “K-bar” was installed. That was never intended to be a long term solution.
The contract for the bridge replacement has been awarded to Dokken Engineering, the same folks responsible in part for the Los Osos Valley Road Interchange project.
Timothy Chamberlain, Dokken’s senior environmental planner for the project noted that the City had some environmental concerns, which his firm had already worked on, with the San Luis Obispo Creek passing through both projects. That includes the presence of red-legged frogs, an endangered species.
“We figure if they’re down stream we need to be careful of them here too,” he said.
The City, and Caltrans both, considers area of Marsh Street to be closed for the project, “ a one-way major arterial connector from U.S. 101 through Downtown San Luis Obispo serving local, commercial, commuter, pedestrian, and bicycle traffic.”
The overall project will replace the existing concrete bridge, which has historical significance as one of the last remaining examples of the designer John Leonard, with a “single span post-tensioned slab bridge.”
When completed the bridge will be restored to it’s turn of the last century appeal, complete with modern light fixtures that are similar to those removed decades ago.
That section of Marsh St, between Osos and Santa Rosa, is expected to be fully closed during construction. However that won’t happen until approximately April next year.
Plans have already been made for dialyses patients to cut through an adjacent parking lot to have access to their treatment center. However, drivers through the downtown area will need to adjust rather quickly, and are expected to.
“It will absolutely be noticed,” said Chamberlain, while gesturing to a diagram of approximately seven affected intersections, “the studies show the impact being spread across the City’s traffic flow.”
Aside from the obvious closures around the bridge, intersections will have light timing changed to adjust.
The project’s Environmental Impact Report is available for public review until March 28 at the City of San Luis Obispo Public Works Department.