click to enlarge Image courtesy of HNTB Corp.

The planned Richmond-San Rafael Bridge bicycle-pedestrian path is scheduled to open in early 2019.

Months before a planned bikeway on the upper level of the Richmond-San Rafael Bridge is scheduled to open, Bay Area transit officials and Marin County politicians are talking about taking the separated bike lane away during peak demand periods.

Earlier this year, Marin County Supervisor Damon Connolly, who sits on the Metropolitan Transportation Commission and the Bay Area Toll Authority, brought up the possibility of converting the soon-to-be bikeway — previously a highway shoulder — into another vehicle lane during rush hour to help alleviate the hellish traffic congestion that plagues the bridge. In early March, the commission's Bay Area Toll Authority Oversight Committee decided to study the idea and allocated $100,000 to the task.

The bike and pedestrian pathway, a piece of infrastructure that cycling and walking advocates have anticipated for decades, is the second part of a four-year pilot project run by the Bay Area Toll Authority. The first phase of the pilot project was the addition earlier this year of a third lane of vehicular traffic on the lower-level eastbound deck of the bridge. That project cost $53 million. The pilot aims to assess possible strategies for improving the Bay Area's transportation infrastructure.

The 10-foot cycling-walking pathway is still set to open in early 2019, and the study is analyzing a scenario that would allow cyclists to continue using the bridge the majority of the time. Still, the oversight committee's willingness to consider excluding bicycles during commute hours worries some cycling advocates. They say granting vehicles access to the lane — even if only during peak commute times — interferes with the state-mandated project of a trail around the San Francisco Bay.

Cycling advocates also believe excluding bicycles during rush hour will significantly reduce the number of people who might otherwise opt to ride bikes to work. Oakland resident and bike commuter Ben Kaufman said a bikeway that is open only some of the time will discourage people from riding their bicycles across the bridge.

"Having access just 18 or 20 hours of the day, and not 24 hours, will definitely discourage ridership," said Kaufman, who's also a professional transportation planner. "When the Bay Bridge [bicycle and pedestrian path] first opened, I didn't know the hours when it was open to bikes, and instead of riding there and risk finding that it was closed, I just didn't go."

He said many would-be cyclists might use the same line of reasoning when considering whether to drive across the Richmond-San Rafael Bridge or bike across it.

Just about everybody in the Bay Area wants to see reduced traffic congestion, but disagreements arise over how best to alleviate the problem. Cycling advocates maintain that making it safer and easier to ride a bicycle, in part by installing a thorough network of protected bike lanes, will be most effective, mainly by encouraging people who would otherwise drive to ride bicycles instead. People who prefer driving their cars argue for building more vehicular infrastructure.

Supervisor Connolly seems to stand somewhere in the middle. He's a part-time bike commuter himself, and he recently wrapped up a 45-day stint of only riding his bicycle and using public transportation — his third year in a row of doing so.

"I'm not the kind of person who sees Bay Area-wide solutions to traffic being centered around adding more lanes to freeways," he said. "But we have a situation here where congestion levels have exploded."

Connolly said the third lane going east, into Richmond, "has significantly cleared up traffic."

He said the overall net benefits of reserving available asphalt for either bicycles or for vehicles during commute hours must be considered. "What we don't want is to have thousands of cars mired in traffic beside very few cyclists using the bikeway," he said.

The westbound bikeway is projected to cost about $28 million to install. The added car lane cost $53 million.

It isn't clear at all, however, that adding vehicle-only lanes alleviates traffic jams. Research has shown that creating more vehicular capacity on roadways does not ease congestion for more than a brief period. Rather, such roadway expansions ultimately produce what is termed "induced demand" or "induced travel," essentially inviting more drivers to use the newly available road space until it fills up again with bumper-to-bumper lines of cars and trucks. A report from the California Department of Transportation describes this phenomenon while advising against roadway expansions as a means of easing the daily traffic hell that plagues the Bay Area's larger roadways, including each of the major bridges that cross the bay.

The Bay Area's gridlock was ranked recently as the fifth worst in the world, and Kaufman said those in favor of more vehicle lanes as a traffic remedy "are mistaken." "When you build more lanes for cars, more cars come," he said.

A freeway expansion in Southern California illustrates this phenomenon. The Metropolitan Transportation authority spent more than $1 billion widening a 10-mile stretch of I-405 between the San Fernando Valley and West Los Angeles. A post-project analysis by INRIX, a transportation analytics company in Seattle, found that cars actually took a minute longer to travel a certain section of the altered roadway than they did prior to the five-year project.

Kaufman said the same principle of induced demand applies to cycling infrastructure.

"Adding a bike lane encourages more cyclists to ride," he said.

Dave Campbell, the advocacy director for Bike East Bay, said making more vehicular lanes on the Richmond-San Rafael Bridge still leaves the onramps and offramps with less capacity.

"Adding a third car lane won't do a bit of good if you don't also widen the landings to and from the bridge in Marin," he said, noting that such a project would pave the way to a slippery slope of roadway amendments that would be prohibitively expensive.

Legislation enacted nearly 30 years ago requires the Association of Bay Area Governments to create and maintain a way for people to walk and ride bicycles around San Francisco Bay. Now, the San Francisco Bay Trail is mostly finished, with a few planned segments yet to be established. The long-awaited pathway across the Richmond-San Rafael Bridge will form a critical link in the trail, and Campbell said excluding anyone who isn't inside a motor vehicle during peak traffic hours could amount to a violation of that law.

"We have a state law saying the shoulder of the bridge should be a bike lane," he said. "Marin County is basically saying, 'Let's forego that state law and address our traffic problem.'"

But those advocating for the auto lane say that allowing cyclists to use it for a token time slot meets the requirements of the Bay Trail initiative. In February, Marin County Supervisor Dennis Rodoni told the Marin Independent Journal that giving the lane over to bicycles and walkers during non-commute hours "will complete the Bay Area Trail and give some relief to our commuters."

Campbell said he feels that Connolly and pro-driving advocates are, in essence, calling for changes that will disproportionately benefit well-to-do vehicular commuters while further disenfranchising low-income residents of Richmond. The so-called Iron Triangle neighborhood of Richmond is already separated from the recreation opportunities of the bay shoreline, Campbell pointed out, and spending heaps of money to accommodate drivers does nothing to help Richmond residents more easily reach the beaches, parks, and trails that line the water.

"The freeway literally creates a barrier between their neighborhood and the Bay Trail. This is a major Title-VI issue that isn't being considered," he said, referencing the section of the Civil Rights Act of 1964 that prohibits discrimination on the basis of race in programs and activities receiving federal financial assistance.

Campbell added that he's disappointed that the four-year pilot project is not looking at potential impacts to East Bay communities of adding a third lane of eastbound traffic and, perhaps, sending more cars speeding through residential neighborhoods of Richmond.

Kaufman said turning a bikeway into a vehicle lane is a step in the wrong direction for a community being choked by almost nonstop gridlock. "People drive cars not because when they were born it was decided they would be drivers," he said. "They're drivers because we make it easy for people to drive. We've created an urban environment that makes it economically advantageous and safer to drive a car. In other cities around the world, they've built systems that make it easier to ride a bike."

Connolly believes granting drivers full use of the bikeway at heavy traffic hours will be one part of a broader effort to ease congestion. "Riding bikes is one part of the solution," he said.

So, he said, are carpooling and public transport.

"But right now there's so much congestion that the buses sometimes can't even move," he said, "and that inhibits people's ability to rely on them."

Editor's note: We misspelled Ben Kaufman's name. This version has been corrected.