If you listen to the public discourse about re-allocating street space to make bicycling safer in San Francisco, a pattern in the naysayers’ message quickly emerges. “Only a small margin of people ride bicycles, and those people don’t deserve space for safer travel,” goes the refrain. “Traffic lanes and parking for cars are too important to give up — trading them for bike lanes won’t get San Franciscans to ride bikes more, it’ll only result in carmageddon.”

Too often, city planners and political leaders give in to these assertions and try to appease the vocal minority of residents who espouse them, scaling back their efforts to make streets safer and more bike-friendly.

But the results of a new poll released yesterday indicate that a significant majority of San Francisco voters think the expansion of protected bike lanes, bike-share, and other efforts to make bicycling more attractive should be a high priority for the city. This kind of public opinion data can be extremely useful for city officials, planners, and bicycling advocates to bolster the case for such efforts, rather than allowing the conversation to be framed by the pre-conceived views of a few curmudgeons.

The poll, conducted by David Binder Research and commissioned by the SF Bicycle Coalition, surveyed 400 San Francisco voters in October. Because voters tend to skew older than the general population, Binder Research noted in a memo [PDF], pro-bike “support would be even higher if these questions were asked of all city residents and not voters.”

The SFBC summed up the findings in a blog post yesterday:

• About three-fourths of voters believe bicycling is good for San Francisco and that bicycling in the City should be comfortable and attractive to people of all ages, from small children to seniors.

• And voters are not just generally supporting the idea of bicycle riding, but are already out there riding a bike regularly. 43% of voters are already riding a bike, with 25% of voters in San Francisco riding regularly, meaning a few times a month or more.

• Two thirds of voters support expanding the bike sharing program to 3,000 bikes to serve San Francisco’s neighborhoods.

• More than two-thirds of voters support the City adding physically separated bikeways to improve safety and traffic flow and to create clearly delineated space for road users.

• Twice as many San Francisco voters are are likely to ride a bike on protected bikeways (56%) than on streets with no dedicated bike space (27%).

• Not only do voters support policies to expand bicycling, there is an urgency to their support – with 62% support for increasing the total number of all trips taken by bike to 10-15% in the next five years.

• Many voters (43%) would like to ride a bike more frequently than they do, including about 3 in 10 of voters who never ride a bike currently. Unfortunately, 53% of voters view current conditions in San Francisco as unsafe for biking.

As the poll results show, most San Franciscans get it: Re-shaping city streets to make bicycling more attractive is not about heeding the selfish whims of a deviant class of “cyclists.” It’s about removing the barrier of intimidating, car-centric street conditions and providing a healthier, more affordable way for a broad range of San Franciscans to get around town, benefitting everyone in the city — even those who never get on a bike.

SFBC Executive Director Leah Shahum elaborated on that point to KTVU at the organization’s Winterfest celebration Sunday:

What we’re seeing throughout the city is a real awareness that more people biking is good for the city. Even for those folks that are never gonna ride, they’re going to benefit as more people bike. Because every time someone like me is on a bicycle, it means I’m opening up a parking space for someone else who needs it. I’m opening up a transit space for someone who needs it, and really helping the city become a safer, calmer, more beautiful place to live and move around.

The poll results complement a growing body of local transportation data that bolster the case for prioritizing bicycling, walking, and transit on the streets. On several urban commercial streets — including Polk Street, Columbus Avenue, Geary Boulevard, and central Irving Street — surveys have already shown that the vast majority of customers arrive without a car. On all those streets, the proportion of car-free visitors has consistently come in roughly around 80 percent. As we’ve seen time and time again, making those streets more inviting to bike on will only increase the share of people who bike there, even if merchants don’t believe it.

The potential for growth in bicycle use in San Francisco can already been seen in its most bike-friendly neighborhoods. As of 2010, the share of work trips make by bike among residents in Hayes Valley and the Mission was higher than 15 percent, according to the U.S. census. Neighborhoods with flatter routes that had calm traffic and bike lanes saw bike commuting grow by as much as 275 percent from 2000 to 2010, census data showed.

From 2006 to 2011, citywide bicycling counts jumped 71 percent, according to the SFMTA, which plans to come out with an updated bicycle count by the end of the year.

Check out a memo summarizing the Binder poll results in this PDF.