The current crossing is also too narrow and creates conflicts between bicyclists and pedestrians trying to negotiate passage, they said.
Palo Alto city officials and consultants from Alta Planning and Design hosted Wednesday's meeting to hear the public's input on five alternatives for a freeway under-crossing or over-crossing.
The year-round crossing would connect the city's residential and commercial areas to the Palo Alto Baylands Nature Preserve, East Bayshore Road, San Antonio Road businesses and the regional Bay Trail network of bike trails. The project will be located north of the San Antonio/101 interchange.
The five alternatives include: renovation of a Matadero Creek under-crossing; a West Bayshore over-crossing; an over-crossing at Loma Verde Avenue; an Adobe Creek over-crossing and renovation of the existing Adobe Creek under-crossing.
The sites are compatible with the Palo Alto Bicycle Transportation Master Plan, Alta Planning Project Manager Allan Calder said. But several had problems with existing power lines, estimated costs or the need to take private property.
Both the existing Matadero and Adobe crossings can be improved to avoid flooding, Calder said. But he pointed to some benefits of a bridge over the freeway.
"An over-crossing in Palo Alto, if elevated 20 feet over 101, would provide a view of the corridor that is spectacular. It could be iconic and a signature piece of infrastructure for the City of Palo Alto," he said.
He presented several designs of overpasses as examples of what such a crossing could look like: A bridge at Highway 101 and Matilda Avenue in Sunnyvale creates a large horseshoe over the freeway; a box bridge links Stevens Creek Trail in Mountain View; a dramatic archway graces a freeway in Berkeley.
But residents overwhelmingly favored the Adobe Creek under-crossing. An over-crossing at the site was the second most-favored choice.
A crossing at Adobe Creek, whether elevated or sub-grade, seemed the most logical choice, since more than 249,000 bicyclists and pedestrians annually cross Highway 101, with 155,000 using the Adobe Creek route, Calder said.
Most people at the meeting noted they live in the Palo Verde, Midtown and Meadow Park neighborhoods.
Palo Alto City Council member Karen Holman said she was stunned by the numbers Calder provided.
"There is a huge demand. It's a wonderful opportunity to do something both creative and utilitarian," she said.
Residents said the Adobe crossing would address many of the growing population issues in south Palo Alto. A crossing there would provide access to Google, Microsoft and NASA campuses and it would be a good tie-in to a proposed Adobe Creek pathway.
Cedric de LaBeaujardiere, Palo Alto Bicycle Advisory Committee, said an improved year-round bike/pedestrian route would create many opportunities to reduce vehicle traffic and increase bicycle usage.
It would also improve safety. Some people take San Antonio Road when the Adobe Creek underpass is closed, he said.
"It's a scary interchange. People do it once and won't do it again," he said.
Jaime Rodriguez, Palo Alto's chief transportation official, said costs for building a crossing will be worked out later and the city will take community input into the design.
Funding for the feasibility and environmental studies are secured, but there is no money to build the crossing. But having that work completed could provide incentive for federal dollars, Rodriguez said.
The City of Sunnyvale built two U-shaped crossings for a total of $8 million and the more elaborate Mary Avenue crossing cost $12 million, he said.
As to the other alternatives presented Wednesday, Calder reviewed the challenges to and opportunities with each.
The Loma Verde over-crossing would offer good bay views and ample space to accommodate ramps compliant with the Americans with Disabilities Act. But it might require taking private property, he said.
The West Bayshore over-crossing — which residents resoundingly rejected — could potentially tie-in to the proposed Matadero Creek trail and a newly constructed trail on the Sterling Canal easement. It offers limited Baylands views, and the ramp might obscure the solar arrays at the city's municipal-services center.
The existing Matadero Creek under-crossing is currently subject, to flooding and improvements would require creek-channel widening to maintain water flow. Existing skylights would also be covered by a Highway 101 auxiliary lane that's planned. It is also the northernmost location, Calder said.
An over-crossing at Adobe would pass under PG&E power lines and could require negotiations to obtain private property for a ramp structure. Costs for building the over-crossing could be higher, according to Calder.
The study will be presented in this fall to the Architectural Review Board, Parks and Recreation Commission and Planning and Transportation Commission. The City Council is expected to review the project next year. The study will be posted on the city's website within the next few days at www.cityofpaloalto.org/101.
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