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.
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
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.
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 today, 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
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. Although at the hearing, I 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 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 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
Thank you for your
help and support.