Considering that due to landslide activity and escalating maintenance costs, this coastal stretch of highway south of Crescent City has long been marred, in a move towards establishing a long-term solution at Last Chance Grade, Caltrans has selected a preferred alternative that could see the construction of a tunnel along U.S. 101 in Del Norte County.
As a step that is essential to advancing the Last Chance Grade Project efficiently, after a consultancy period Caltrans has elected for Alternative F, a 6,000-foot tunnel that bypasses area landslides and realigns the highway, whereas this suggested tunnel would be the longest constructed in Caltrans history.
The intention is that the resulting decision should maximize long-term reliability, following lengthy discussion with tribes, environmental groups, lawmakers, and other stakeholders.
This tunnel which prevents chronic landslides, coastal erosion, and the impacts of climate change while ensuring safety during seismic events, has the construction cost of almost $2.1B in 2031 dollars.
Considering that there are the sensitive environment and potential impacts on large-diameter, old-growth redwood trees, the proposal still faces challenges and Caltrans is committed to delivering a successful project through partnership, community support, and collaborative mitigation efforts, exploring all avenues to stay on schedule while prioritizing quality, efficiency, and preservation.
Re-engineering the existing route in the hopes it would be resilient among the area’s mapped landslides, was the alternative X, which wasn’t selected.
In order to realizing this project, Caltrans continues to seek all possible funding opportunities and the project has remained on schedule and on budget while the project team is on track to finalize its environmental document by late 2025.
In the next year more design refinements would occur, while for staying on track, it is important to fund design, support, right-of-way acquisition, and other costs by December 2025, and it would require to fund construction costs by 2029.If in term of preparing all goes according to plan, construction could commence as early as 2030.
If that happens, the tunnel could be open as early as 2038, however, Caltrans is looking for any and all opportunities to accelerate this timeline.