California’s Highway Dilemma: A Costly Fix for a Troubled Route
California’s taxpayers may face a hefty bill—potentially in the billions—to preserve a crucial coastal highway that is literally sliding into the ocean.
The California Department of Transportation (Caltrans) is considering a plan to dig a 1.8-mile tunnel through redwood forests. This would bypass a deteriorating stretch of Route 101, known as the “last chance grade.” The project’s estimated cost? A staggering $2.5 billion.
It’s worth noting that this price tag comes after over ten years of research and planning, topped off with a 712-page environmental impact report released in late May, which had a price tag of $55 million.
Next on the agenda for Caltrans is to request $225 million from the California Transportation Commission later this summer just to kickstart the tunnel’s design phase and enlist international experts in seismic tunnel construction.
The focus is on a nearly three-mile stretch of highway in Del Norte County, precariously clinging to foggy cliffs and surrounded by ancient sequoias along the Pacific coastline.
This stretch of road serves as the sole link for Crescent City—a tsunami-prone town with about 6,000 residents—to Humboldt County and beyond. When the highway is closed, travelers are forced to take a grueling 449-mile detour through Redding and southern Oregon, or navigate steep dirt logging roads.
Interestingly, this instability is not a new issue.
The corridor started as a bridleway back in 1894 and was reconstructed in the 1930s, despite early warnings from engineers about land shifts complicating maintenance. Those warnings turned out to be spot on. A feasibility study from 2015 noted, “numerous falls and slips occurred during construction, which delayed progress.”
Currently, the highway is home to four active landslides, making it one of the most problematic routes in California. It was reduced to one-way traffic for nine straight years, and even though it briefly reopened in October 2023, it has faced ongoing restrictions since then.
Additionally, the ground beneath the highway has shifted dramatically since the 1930s—by up to 40 feet horizontally and 30 vertically—while certain sections now seem to inch several feet closer to the ocean each year.
Attempts to stabilize this highway have not fared well. Over 20 retaining walls constructed over the years have either cracked or shifted in response to ongoing slope movement.
There was even a tragic incident in 1972 when a couple’s car went off a cliff due to a pre-dawn collapse.
The proposed solution? An eastbound tunnel designed to bypass the most treacherous areas. At 6,000 feet long, it would become California’s longest highway tunnel, surpassing the 4,233-foot Wawona Tunnel found in Yosemite National Park.
Still, this fix isn’t without environmental concerns. The planned route runs through Sequoia National and State Park, a UNESCO World Heritage Site, and would necessitate the removal of 16 old sequoia trees, each more than 4 feet wide, among others as outlined in the environmental report.
Jaime Mateoli, the Last Chance Grade project manager at Caltrans, emphasized the importance of this investment, despite the challenges involved.
“This is a proud moment,” he stated. “The safety of our roads significantly impacts people’s quality of life, and there is widespread recognition that this project is necessary.”
If funding comes through, construction might kick off around 2031, with the tunnel opening projected for 2039.
