Architects from Palo Alto and beyond could soon be asked to flap their creative wings and help the city design a new bridge that would span a busy highway and give residents in the south part of the city an elegant, year-round entry point into the Baylands.

The bike bridge, which would stretch from south Palo Alto to the Baylands and span U.S. Highway 101 at Adobe Creek, is one of the most ambitious and expensive proposals in the city's recently approved Bicycle and Pedestrian Transportation Plan. It seeks to replace an existing underpass at Adobe Creek, a structure that is closed for much of the year because of flooding.

The $10 million project got off to an auspicious start last year when the city succeeded in landing a $4 million grant from Santa Clara County for design work. Now, officials are preparing to delve into the nitty-gritty. Last Thursday, Feb. 21, the Architectural Review Board held a public hearing on the proposed overpass and heartily endorsed the staff proposal for a design competition -- an exercise that city officials hopes will lead to a surge of creative ideas.

"I'm very much in favor of a design competition," member Randy Popp said. "There are only things to be gained from it and nothing to be lost."

On Thursday, the board considered some parameters for the competition, including the judging process and the criteria designers will have to follow. Board member Lee Lippert said the design should strike the fine balance between functioning as a "gateway" to Palo Alto and Silicon Valley and blending in with the natural beauty of the Baylands. It should be a landmark, he said, without becoming a blemish.

"It can't be overdesigned," Lippert said. "It can't impose itself on the open space."

Lippert called the design competition an "incredibly good idea" and proposed that the city adopt four criteria: simplicity of design, sustainability, compatibility with natural open space and enhancement to the pedestrian and bicycling experience.

Board Chair Clare Malone Prichard voiced support for Lippert's criteria and shared his enthusiasm for the competition, urging staff to cast as wide a net as possible. The contest, she said, should be "really inclusive."

"You can be surprised at some of the ideas that come from students, locals or internationals," Malone Prichard said. "You don't want to limit the opportunities by selecting just a few design professionals to compete."

While the competition idea is still being worked out, city staff is busily proceeding with other aspects of the bridge project. Elizabeth Ames, project manager with the Public Works Department, said staff is working with the state Department of Transportation to complete the mandated federal and state environmental reviews.

Staff and its consultant, Casey Hildreth from the firm Alta Planning + Design, are also considering, in broad terms, the type of bridge the city should seek.

At Thursday's meeting, Hildreth presented three alternatives: a "landscape" bridge that emphasizes the natural setting; a "signature" bridge that is fancier and functions more as a landmark; and a "post-modern" bridge -- a catch-all term to describe highly eccentric ideas that a design competition will likely attract.

Hildreth acknowledged that given the location of the new structure, he is slightly biased toward the first of these options.

"Really, we shouldn't be thinking about this bridge intruding," Hildreth said. "It should really be an extension of the park over the highway and into the community."

While the board didn't vote on the project Thursday, members said they were enthusiastic about the project. Board member Alex Lew, a bicyclist and frequent Baylands visitor, said he uses bridges throughout the Peninsula and finds many of them too narrow or deficient in how they were designed. Like Hildreth, he said he supported emphasizing the bridge's Baylands setting. This could mean "more horizontal and less vertical," he said.

According to a report from Public Works staff, the environmental review for the new bridge is set to be completed later this year, in the fall or winter. If the City Council opts to proceed with the design competition, it would take place between summer and winter of this year, with the final design completed some time in 2014. The city's goal is to secure all the needed permits and begin construction in fall 2015 and to have it completed by late 2017.