Standing since August 1969, the San Diego-Coronado Bay Bridge represents different things to different constituencies. Some consider the 2.1-mile span to be the signature piece of public art of the region, while others deem it the sole source of a complete spectrum of traffic problems in Coronado. The bridge is owned, operated and maintained by Caltrans.
Most recently, the bridge served as the inspirational spark for the grand idea of constructing a combination bicycle/pedestrian tube, through the center archways of the bridge. The ‘minimum criteria tube’ would be 13.7 feet in diameter, while the ‘expanded criteria tube’ would be 18.12 feet in diameter.
To his credit, San Diego County Supervisor Greg Cox has long held the vision of having a completed bikeway that would traverse the entire Bayshore area. Two years ago, the county of San Diego funded a study to the tune of $75,000 to determine if the tube project was feasible. The results came in the form of a 59-page report, plus appendices, prepared by HNTB Corporation, an architecture, civil engineering consulting and construction management firm based in Kansas City, Missouri. HNTB Associate Vice President Liz Young, who works out of the firm’s Los Angeles office and concept creator and architect Lew Dominy presented the report to the SANDAG Bayshore Bikeway Working Group meeting held Thursday, March 30, 2017.
Cox chairs the committee and representing Coronado at the meeting was City Councilmember Mike Donovan.
The study indicated on page 58, under the heading, ‘Constructability and Cost Options,’ that, “Similar to the assessment for the alignment, geometry and structural feasibility, the team did not identify any fatal flaws for constructability and cost, but there are challenges associated with the construction of the proposed facility.” There were three tube location options outlined in the study. They included the ‘Pier Archway Alignment,’ the ‘Pier Cap Alignment’ and the ‘Bridge Deck Alignment,’ with the latter option anticipated to block the view of motorists on one complete side of the bridge.
Some quick background regarding the San Diego-Coronado Bay Bridge is required at this point. The bridge was constructed using 36 vertical towers or ‘Piers,’ the tallest of which tops out at 200 feet above the Bay. The primary navigational channels are between (counting from Coronado to the east) Piers 18-19, which has a channel width of 270 feet from side-to-side, and Piers 19 and 20. According to the feasibility study, the proposed bike/pedestrian tube would be, “Approximately 30 feet below the required 197.12 feet of clearance from mean sea level.” The study characterized the situation as, “The conflict point at the navigation channel between Piers 18 and 19.”
Contrast that relatively rosy approach to the response to the tube concept supplied in correspondence from former Commander of Navy Region Southwest, Rear Admiral Markham K. Rich, which said in part, “The height of 195 feet above Mean High Water (MHW) tide level directly below the inbound vessel transit lane piers 18 and 19 and a maximum height of 214 feet below the outbound vessel transit lane piers 19 and 20, allows U.S. Navy ships operating out of Naval Base San Diego and civilian cargo vessels operating out of National City Marine Terminal as well as the NASSCO Shipyard to pass underneath the bridge within designated transit lanes. The largest Navy vessels to pass under the bridge are the four large-deck amphibious assault ships homeported at Naval Base San Diego. These ships have a height above the waterline that reaches 192 feet, depending on ship type and mission load out configuration affecting the vessel’s draft. Therefore, any alternative of the proposed project which reduces the current minimum clearance of 195 feet between spans 18 and 20 would impede Navy vessel traffic and would not be supportable due to mission impact.”
And while we are on the subject of potential fatal flaws, the cost estimate for any of the three options detailed in the report is between $185 million and $210 million. But even those figures aren’t complete.
Councilmember Donovan reflected on the pedestrian/bike tube concept the morning after the Bayshore Committee meeting. “I thought it was good work they put together, which was a high-level feasibility-type study. It’s an interesting concept. My view is there are some concerns I would have that aren’t addressed in the study. First of all is the cost. As Supervisor Cox pointed out, when this started it was $50 million to $60 million and now it’s up to $210 million in 2015 dollars. So, you can add another 10 percent for inflation and that’s a lot of money. Plus, there are a lot of other priorities such as finishing the current Bayshore Bikeway to complete the loop before we even consider this. And there were practical issues brought up in the study, like safety access if somebody has an accident or there is an immediate medical emergency midway, it would take somebody quite a while to get there.
“We are finding out on the Strand part of the Bayshore Bikeway that people are clamoring to make it wider. Pedestrians and people riding bikes are causing congestion and safety problems. If we have the money and built the bike/pedestrian tube on the Bridge, it would only be a matter of time before we were having congestion and safety issues there as well. A full-up structural analysis would have to be done to make sure the bridge meets seismic requirements. The cost estimates didn’t include the cost of Caltrans modifying the maintenance platforms and the things they would have to do to maintain the rest of the bridge and the (proposed) tube. As usual, there is more cost than the original estimate would tell us. That’s not a criticism of the study, which was advertised as a high-level feasibility study. After that initial estimate, it would be hard to spend any more money at this point, pursuing the project in the future.”
Another challenge is access and egress to the proposed tube, options for which would include a small portion of Chicano Park under the bridge on one side and the Coronado Municipal Golf Course on the other. It would be an interesting intellectual challenge to assess which option is least likely to happen.
A personal favorite was the four-page opinion letter from Caltrans attached as an appendix to the report, which delineated the 13 governmental agencies that are required to sign off on the project before it could proceed. The agencies include at the local level, the Harbor, the City of San Diego, the City of Coronado, the Unified Port of San Diego and the Coastal Zone; state agencies would include the California Highway Patrol, California Fish & Wildlife, and the State Historic Preservation Office; and Federal agencies include the U.S. Coast Guard, U.S. Fish & Wildlife, the U.S. Navy, the U.S. Army Corps of Engineers, and Homeland Security.
Donovan said, “I wouldn’t say we shouldn’t do the project just because of the approvals that are needed, but that would certainly add time and effort. It took us (the city of Coronado) 20 years to get a new fence on the state park on the Strand.”
After the consultants concluded their presentation at the March 30 meeting, Donovan asked Cox, “What is the next step?” Cox replied, “I don’t know that we have a very good answer. The study was funded through the county and there is no money identified for construction for the tube. Again, we have had a lot of bike projects in the queue for a long time, for the Bayshore and other trails, and this project won’t step in front of anybody.”
And there in a nutshell, is the fatal flaw for the San Diego-Coronado Bay Bridge Bicycle/Pedestrian Tube Plan going forward.