OK, I'll say this from the start: I am not a libertarian, and will most likely get some of the finer points of libertarian ideology wrong. For that, in advance, I apologize. But, like most people, I am not above co-opting other people's political leanings in favor of advancing my own agenda.
So let's get started.
While auto-centric Rob Ford-style "libertarians" have consistently attacked cyclists, it's always seemed to me that bike-friendly development ought to be a no-brainer for true libertarians. Like the ideologically consistent libertarians who champion distributed clean energy, or my deeply libertarian friend who is vehemently opposed to Keystone XL because of his hatred of eminent domain (and his belief in the validity of climate science), there ought to be—and probably are—countless libertarian-leaning folks who understand that bikes are a valuable tool in the advancement of freedom.
Biking is about freedom of choice
Free marketeers can talk about freedom of choice all they like, but if everything is built around dependence on the motorcar, that freedom is an illusion. I may choose to bike with my kids in a not particularly bike-friendly town, but there are a myriad of obstacles put in my way—and those obstacles can be life threatening in many localities. Providing well-designed bike infrastructure ought to be a prerequisite for true freedom of choice when it comes to transportation.
Biking promotes self-reliance
From teaching kids that hard work pays off, to enabling people of all ages and socio-economic backgrounds to move about safely and efficiently, besides walking, bicycles are the most self-reliant form of transportation I can imagine. Heck, they are even easily maintained and repaired at home, meaning they encourage new skills and taking responsibility for yourself.
And that's before we even get into the arguments about energy independence and freeing ourselves from the market-manipulating hegemony of Big Oil.
Bikes improve public health
Don't like Obamacare? One of the best ways to avoid over-reliance on public (or private) healthcare is simply to keep people healthy. And if you remove the barriers to human-powered transportation, you see more and more people voluntarily incorporating healthy exercise into their daily lives. Coincidentally, as more people bike, the streets get safer too—meaning fewer accidents, and fewer people suffering the consequences of other peoples' bad decisions. If that's not consistent with true libertarianism, I don't know what is.
Bikes can advance small government
Despite the silly Agenda 21 conspiracy theorists, even a cursory understanding of bikes and bike culture would suggest biking reduces the opportunities for government to intervene in our lives. Just watch bike traffic in Amsterdam: there's no helmet mandates, there are relatively few traffic signals or controls, and—to be honest—cyclists don't exactly follow all the rules.
Instead, they use their sound judgment and ability to communicate with one and other to navigate through traffic and keep each other safe. It might look like chaos to the uninitiated, but in fact negotiated traffic safety works remarkably well once speeds are reduced to a pace that human interaction is enabled. (Bikes are also quite hard to tax, license or regulate, which should make the hardcore libertarians happy!)
Bikes support small business
From specifically bike-related repair, retail and delivery businesses to the cafes, boutiques and (of course) bars that cyclists love to support, bikes are an economic boon for businesses that don't require massive amounts of capital to get off the ground. That's why LA is launching its first bike-friendly business district, and we suspect it won't be the last.
Bike infrastructure is fiscally responsible
Zach posted this chart recently in his excellent piece on the rise of protected bike lanes in America, but it is a profoundly important demonstration of what we are talking about. So I'm going to steal it.
There is no form of transportation that requires more subsidies and government support, and does more to curtail the freedom of those who don't chose to use it, than the motorcar. And by contrast, what's the cheapest, simplest form of public infrastructure to build and maintain?
You guessed it...