Long-awaited plans for a bike and pedestrian bridge into the heart of Mountain View's North Bayshore tech campus are beginning to take shape, designed with an eye toward getting workers from the downtown transit stations to one of the most dense job centers in the North County.
Early designs for the highway overcrossing, reviewed by the City Council Tuesday, envision a large 20-foot-wide bridge along Shoreline Boulevard that would take bicyclists and pedestrians over Highway 101, creating a safer path to North Bayshore away from highway on-ramps and off-ramps.
The dedicated pathway will start on Terra Bella Avenue and reach north to Pear Avenue, and will have two 7-foot lanes for bikes traveling in both directions. Though there will be a lane available for pedestrians, city staff say the design is intended to cater to commuters biking from downtown Mountain View to companies like Google and Microsoft.
"This is definitely being planned toward commuting," said Public Works Director Dawn Cameron. "We will see pedestrians, but the bridge itself is over half a mile long. The primary users are going to be bicyclists."
The bridge should have more than enough capacity to handle the city's goal of getting 1,700 bikes and pedestrians in and out of North Bayshore during peak hours, representing a 10% shift away from solo-vehicle drivers clogging up traffic. It also pairs with the city's goal of designing a more urban area of the city with limited roadway capacity and parking.
Current bike and pedestrian traffic into North Bayshore is pretty far off the mark. At the highest peak hour, 150 commuters are using Stevens Creek Trail, 90 are using Permanente Creek Trail and 22 are using Shoreline Boulevard.
While the planned bridge would be one of the largest bike and pedestrian bridges in the area and a significant link between the city's transit hub and thriving employment centers, the design plan is anything but ambitious. City staff say the plan is to use a "concrete box girder" design similar to the Permanente Creek Trail over Highway 101 and the Stevens Creek Trail bridge over Highway 85.
The choice was described by staff as a pragmatic approach to building bike infrastructure, a way of managing the design, construction and maintenance costs. As it stands, the project would take an estimated $2 million to design and $20 million to build. A spectacular design would also be somewhat of a waste -- due to its location, the vision of the bridge is heavily obscured in both directions from Highway 101, hidden by trees, the Shoreline Boulevard overpass and the Old Middlefield Way flyover.
The decision stands in deep contrast to Palo Alto's Highway 101 bridge plans at Adobe Creek. The city initially sought to create an iconic structure through a design contest in 2011, only to later scrap the idea when costs ballooned. A more scaled-back version of the project was finally approved in November.
Mountain View City Councilman Chris Clark said he wondered whether the Shoreline bridge could still include some type of aesthetic elements to make it more interesting. Though Caltrans has to give its blessing and generally opposes driver distractions, he suggested the bridge be designed to light up or have some kind of back-lit art that can be seen from below.
"I think some of the most interesting bridges I've seen are actually the most interesting at night," Clark said. "I know Caltrans is a hurdle there, but I think that would be a low-cost way to make something that's a pretty standard design stand out."
Less enthusiastic was Councilwoman Alison Hicks, who said a more lightweight design would look better and better match the urban environment of North Bayshore. She cited a popular example in Copenhagen, and suggested that such a design could be cheaper and more appealing.
"I would like (the design) to be at least looked into to be part of our network, so I may not be voting for this if that puts it on staff's to-do list," she said.
Full conceptual designs will be ready by early 2021, with no specific date for when construction begins. The city will be using its Shoreline Regional Park funds to pay for the design, but has yet to decide where the $20 million construction cost will come from.