Beginning in 1958, California began the process to replace Devil's Slide with an inland route over Montara Mountain, known as the Martini Creek Bypass.

A Caltrans study in 1974 determined that a tunnel would be a viable alternative to the current road or a proposed inland freeway bypass.

However, the Sierra Club sued to stop construction, as California law requires that State Route 1 be restricted to two lanes in rural areas.

In April, Caltrans documents were discovered that showed the agency had intentionally overestimated the costs of a tunnel, to support the freeway bypass.

On November 9, Caltrans changed its position, supporting a bridge and tunnel as the best environmental, economic, and popular alternative to Devil's Slide.