Ten Mile Bridge Replacement Project

News and Developments

The Ten Mile Bridge is the third replacement project of Caltrans on scenic Highway 1 in Mendocino County.

The first one, the Noyo Bridge, led to a protracted, ultimately successful effort to get Caltrans to use a railing design that was visually pleasing, protected pedestrians, and allowed virtually unobstructed views.

The second one, the Greenwood Bridge, in the small village of Elk, led to another so-far-successful battle (as of June 2006) to protect the coast from an urban-expressway style bridge.

Background

Ten Mile Bridge is located in a rural, ecologically sensitive, and scenically beautiful location in Mendocino County.

In Fall, 2005 Caltrans proposed to replace this bridge with one that is completely out of character and scale, lacks a protected sidewalk, and uses a railing that obscures views and lacks any grace or historic character. Caltrans made this proposal despite Coastal Commissioners expressing their opposition to it at an earlier hearing on the Greenwood Bridge.

The 8' shoulders will give the bridge the appearance of a high-speed expressway, rather than a scenic bridge on a rural road.

The lack of a sidewalk will endanger local people and those using the Coastal Trail.

The proposed railing is appropriate for a cattle gate, not a scenic bridge.

A sidewalk with a protective rail on the inner, traffic side, as on the Noyo Bridge,  would be much safer. A newly designed outer pedestrian rail would be more aesthetic and less visually obtrusive to motorists and, especially pedestrians and bicyclists.

A hearing before the Coastal Commission was scheduled for November 2005. The task of defeating this project was made doubly difficult by the crucial support of the Commission staff for the Caltrans design. Because of the overwhelming amount of information that confront the Commissioners at every monthly meeting, they rely heavily on the recommendations of the staff.

For detailed support of recommended amendments, see  Ten Mile Bridge testimony to the Coastal Commission (requires free Adobe Acrobat Reader). Caltrans arguments for 8' shoulders are completely unsupportable, based on an analysis of state and national design standards, design exceptions, and accident data.

The Coastal Commission staff report on the Ten Mile Bridge is at:
www.coastal.ca.gov/cd/W20b-11-2005.pdf. There is a long, tortured attempt to rationalize the acceptability of 8' shoulders on pages 17-22. It is not convincing.

The Ten Mile Bridge effort is part of a campaign to preserve scenic views and the rural character of bridges along coastal Highway 1. Find out more.

News and Developments

June 10, 2006, Santa Rosa. The Coastal Commission approved without discussion a revised Caltrans proposal for the Ten Mile Bridge. The revised design has a single five-foot sidewalk on the west side, six-feet shoulders on both sides, and a combination auto-bicycle railing on the east side.

The revised design was Caltrans' response to the Commission's November, 2005, specification of four-foot shoulders and sidewalks on each side of the bridge. From the standpoint of preserving the scenic values of Ten Mile River, the revised design is mixed. On the positive side, the single five-foot sidewalk reduces the scale of the bridge as compared to two four-foot sidewalks. The six foot shoulders are unnecessarily wide from an automobile safety standpoint, but five-foot shoulders are recommended for bicycle safety; thus the arguably unjustified width of the bridge is only two feet.

In a welcome move, Caltrans and the Commission agreed to defer for a year choosing a design for the railings on the bridge. The design of the railing for the east side of the bridge is challenging, because it will need to protect bicyclists as well as cars. The initial design proposed by Caltrans was a visual catastrophe – suitable for a cattle gate, but not a scenic bridge.

Since November, Caltrans and a subcommittee of the Commission have been working on developing alternative designs. I was invited to assist the subcommittee and have been doing so. To date, no really attractive designs have been developed, but Caltrans seems open to meeting the concerns of the Commission and the public.

[Just this week, (June 27, 2006)I received extremely good news that creates a much greater probability of making a visually attractive and transparent design for the east railing: the national highway standards organization followed by Caltrans has just lowered the bicycle railing height from 54" to 42" (the same as pedestrian railings). This will improve enormously the aesthetic possibilities for railing designs.]

The most discouraging aspect of the Ten Mile decision was the Commission's acceptance of bogus "safety data" from Caltrans. The Commission staff and ultimately the Commission accepted the wider shoulders because Caltrans asserted that moving from four to six foot shoulders would reduce accidents by 44 percent.

I was not provided the source of the Caltrans safety estimate until after the Commission staff had published its staff report, too late to provide correct information to the staff and too late even to get written comments to the Commissioners until the night before the hearing. It is doubtful that any Commissioners even reviewed my written testimony (free Adobe Acrobat Reader, if needed). Although at the hearing, I that showed that there was no empirical basis for Caltrans' safety assertion and that there was no significant vehicle safety benefit from the wider shoulders, it was too little too late.

On the positive side, Caltrans has invited me to work with me on future bridge designs prior to submitting permit applications to Caltrans. I've accepted the invitation and hope to come to resolve our differences around safety arguments. The evidence on shoulder width and safety is very clear. I am optimistic, therefore, that future coastal bridges will be built with the five-foot shoulders that are needed to for cyclist safety and no wider.

All in all, progress is being made, largely because of the outpouring of public support for bridge designs that protect the scenic values of our beautiful North Coast.

Thank you for your help and support.