Other proposed enhancements would raise the price of the new bridge, according to a new report from the Public Works Department. They include a plaza at the eastern approach ramp ($420,000), enhanced railings and fencing ($470,000) and enhanced amenities such as benches, signs and drinking fountains ($130,000).

In discussing the new plans from Biggs Cardosa (the firm that the council chose last May to replace Moffatt & Nichol), the council will consider a range of enhancements that would make the bridge less basic and more eye-catching. The proposed $13-million structure already includes several such features, including an overlook platform on the eastern approach and separated bikeways on streets leading up to the bridge ramps.

Designed by the firm Biggs Cardosa, the structure now proposed for Adobe Creek represents a reset of sorts from the ribbon-like bridge that the council favored last year, a design that came out of a competition that the city launched. While the slender bridge designed by a team led by Moffatt & Nichol didn't win the design contest (the official winner was a more prominent, arch-like structure designed by a team led by HNTB), council members found its understated design to be more in keeping with the Baylands vibe.

But after determining last December that the slender, elegant bridge of their dreams would exceed the city's $13-million budget for the project, the City Council agreed to settle for a more standard and affordable alternative. Just how standard and how affordable? That's the question that council members will debate on Nov. 7, when they get their first look at the preliminary designs for the proposed structure.

When Palo Alto officials set out to build a bike bridge over U.S. Highway 101 five years ago, the plan was to create the city's next landmark -- a structure that would provide yearlong access to the Baylands and make passing motorists take notice and say “Wow!”

The bridge project was also on track last year to receive a $4.65 million grant through the One Bay Area Grant program, though that contribution was one of several that was scuttled by the California Transportation Commission because of a funding shortfall. While city officials still expects to get the state money in the months ahead, as part of the second round of One Bay Area Grant, they also recognized during the May discussion that it's simply too soon to know exactly how much money the city will have on hand to build the new structure.

Though the bridge is expected to ultimately cost at least $13 million, the city won't be shouldering the expenses alone. The project has already received a $4 million grant from Santa Clara County, with the money coming from recreation fees contributed by Stanford University. Google has indicated that it would be willing to contribute $1 million toward the project. Palo Alto officials also hope that Stanford University's recent decision to forego a $4.5 million county grant for a new trail network means that the money could now be made available for the Adobe Creek bridge (the county's Board of Supervisors has not yet indicated whether it would redirect these funds to Palo Alto).

Yet another alternative omits the arch altogether in favor of a more minimalist feel, with only the sky above the users' heads, while another does the exact opposite and creates a latticed roof over the span. Then there is the most expensive one: an enclosed, three-span truss that resembles a series of gently sloping arches and that would add about $2.9 million to the baseline price tag (the others would add between $710,000 to $2.25 million).

In addition, there are five different alternatives for the steel truss that will support the new bridge. According to Biggs Cardosa renderings, the baseline option (known as a “three-span bowstring truss”) resembles a steel skeleton stretching from the eastern approach to the west, with a large arch in the middle, along the main span. Another option calls for a one-span bowstring truss, which includes the arch but omits the steel supporting structures on either side of the arch.

The most expensive and dramatic enhancement on the menu is increasing the width of the bridge from 12 to 16 feet. The wider structure would allow for 12 feet of continuous clear width, thus making it possible to separate bicyclists and pedestrians.

If things go as planned, design work and environmental analysis for the new bridge will progress over the next year and conclude in 2018. Construction would begin in early 2019 and be completed in early spring of 2020, according to the timeline from the Public Works Department.

But the council isn't banking on additional county funds just yet. Chastened by the recent experience with the design competition, Vice Mayor Greg Scharff was one of several council members who in May urged caution in considering enhancements to the bridge. He said he would be concerned about “going to the community and getting people excited about stuff, like we did with the design (competition), and then pulling it back and saying you can't have this beautiful bridge, you can have that bridge.”

Palo Alto explores new direction for Baylands bike bridge

Council weighs financial constraints and desired enhancements for overpass at Adobe Creek