Fog Report
by Peggy Bechtell
Montara

The issue of fog on the by-pass has not been addressed accurately by Caltrans.

I would like to submit the following information for your consideration:

• The height of the current road (Devil's Slide) is 300 ft.
• The bottom of the fog layer that comes in from the ocean is 500 ft.
• The proposed saddle-cut on the by-pass is at 700 ft.

We are all familiar with the difficult driving conditions in fog at the intersection of Hwy l at Skyline, before it drops down into Pacifica. USGS states that this intersection is at 625 ft. This means that the by-pass would be seven stories higher than this intersection.

For one year ('85-'86), I documented each day that the saddle cut was totally obscured by dense fog during morning and evening commute hours (6 am-9 am and/or 3 pm-6 pm).

There were 193 days of heavy fog out of 365 days at the by-pass elevation during commute hours. This was 53% of the time. There were 5 days of fog on the existing road which was 1%. This means that the fog problem would be 52 times greater.

I compared and documented my findings with the Annual Summary of Local Climatological Data from San Francisco International Airport.

My concerns are substantiated by Jindra Goodman, a fog consultant hired by Caltrans, who stated in her written report to them:

"August and September have a mean fogginess greater than 50% of the time for all times of the day.......fog frequency and density increases with elevation. If a cut is made in the ridge saddle.....this will result in higher winds and an increase in fog frequency."

Her findings were omitted by Caltrans in their final EIR.

The California Coastal Commission Staff Report in June, 1985, also states:

"The inland bypass would be at higher elevations and would be significantly foggier than the existing alignment or the MDA....the large cut at the saddle peak will probably exacerbate the fog hazard."

The report goes on the state, " Caltrans' fog analysis relied on out-of-date standards for stopping sight distances."