As someone with a background in architecture and civil engineering, I am disappointed to see a respected colleague (Fred L. Sweeney’s letter in Voices, Jan. 24), express opinions that are factually incorrect as well as technically problematic.
The title and first sentence of Mr. Sweeney’s letter immediately raise many questions: “Mission Canyon bridge needs reconstruction” — it doesn’t — “to solve access and safety problems.”
There aren’t any problems that cannot be solved with simple measures.
The Wallace Group was given an impossible assignment: to find a feasible solution based on demolition and reconstruction that will improve current conditions without destroying a unique historical, aesthetic and engineering jewel that is an integral part of the Mission Historical Park.
The group has so far completed alternative sketches for “flattening” the curvy road section around the bridge, as well as for the bridge itself.
They did their best under the circumstances, considering the issue from many angles, and producing attractive visualizations of three alternatives each for the bridge and road section. These were presented during a webinar in December.
What a waste of effort and resources.
The Coalition to Preserve Mission Canyon has collected abundant material and opinions from a variety of official sources and city and county experts that show that:
1. The bridge is in very good structural condition and causes no safety concerns. Minor, very local repairs are possible and desirable.
Celebrating its 120th birthday this year (note: many similar stone bridges from Roman times are still in use in Europe), our bridge has seen its share of floods and the largest earthquake to hit Santa Barbara in historic times.
Further, its status for being eligible for the National Register of Historic Places means that by law, any structural interventions have to abide by California Environmental Quality Act and the U.S. secretary of the interior’s Standards for the Treatment of Historic Properties. Remodeling and redesigning are not recognized treatments.
2. On the Option 3 bridge design, recommended as “most feasible” by the Wallace Group and enthusiastically endorsed by Mr. Sweeney and the Mission Heritage Trail Association: The single-span bridge is a skew arch bridge, meaning that the ends of the arc meet the vertical supports or foundations at an angle. This design is inherently unstable because it creates lateral forces that tend to flatten the arch.
There are, of course, many different methods for building safe skew arch bridges, but these are complex and expensive and take longer to complete. Also, a skew-arch bridge would not meet the National Register criteria for a historic pace.
3. “Flattening” the curve is a surprising idea. All this will do is to speed up traffic, creating a dangerous situation at the busy T-junction with Mountain Drive.
It is also unnecessary. The Coalition to Preserve Mission Canyon has a large volume of data from the California Highway Patrol, the Santa Barbara Police Department, and from local newspapers and other sources for 2001-2020. While the database may not be complete, it shows that accidents on the Mission Canyon corridor are few and not serious. None of the collisions involved pedestrians or cyclists.
The corridor is as close to Vision Zero as can be hoped for a moderately busy two-lane road. Improvements in signage and other minor interventions are possible.
There is one thing in Mr. Sweeney’s letter that I wholeheartedly agree with: Nature’s force can be deadly.
Taking the bridge and Mountain Drive’s T-junction out of commission for any length of time can indeed be deadly in case of fire for those living and working on the west Riviera, the oldest and densest part of a residential area that is officially declared to be among the most fire-prone in the state. The west Riviera also includes a number of conditional use permit facilities that more than triple the residential population: There is a K-9 school, a 92-room hotel with restaurant, an industrial park, a movie theater and a hospice facility. In case of fire evacuation, the only reasonable exit for that area is the Mountain Drive T-junction and the bridge, considering that the fire will most likely be coming from the east with the Santa Ana winds and that the bulk of the Riviera residents to the east will be using the Lasuen to Alameda Padre Serra exit, the west area’s only other option.
I would thus accept the risk of a 100-year-flood taking down the bridge 100 times more readily versus the very real and probable threat of a wildfire on the Riviera during the inevitably long demolition-reconstruction period, when the bridge will not be available for evacuation or first-responder access.
A shiny new bridge is not worth the lives of possibly dozens of people.
The author lives in Santa Barbara.