A bicyclist uses a bike lane along L St. NW in Washington, DC. (Photo by Matt McClain for The Washington Post)

In full disclosure, I have scoffed the law while cycling. In my neighborhood at night, when there's no one around, I have rolled through a stop sign. I have paused at an intersection, "no turn on red," and then done exactly that on a bike. I do these things ... occasionally.

"I do, too," says Wesley Marshall, now that we're confessing. "If I’m sitting at a red light next to a bunch of cars, and there are no cars crossing, I’ll go through the red light to establish myself in the street in the next block, because I feel like I’m safer doing that."

I have done this, too, and for the same reason: because it feels less dangerous to get out ahead of traffic than to fight for space on a road with no bike lane at the moment when the light turns green. Marshall, an assistant professor of civil engineering at the University of Colorado Denver, suspects, though, that many drivers may not understand this thought process — that seemingly bad biking behavior is sometimes an act of self-defense.

Perhaps that's because we don't really understand — and we definitely don't talk about — the behavioral psychology of cycling all that well. Maybe drivers picture all scofflaws as that caricature of a New York City bike messenger, a professional risk-taker who laughs at traffic laws and the suckers who obey them.

"I don’t think everyone who’s breaking a law on a bike is that person," Marshall says. "You’re not that person. I’m not that person. I don’t feel like I’m risking my life when I’m doing these scofflaw behaviors — I feel the opposite."

There is, in fact, a lot we don't know about why cyclists behave the way they do, or even what happens when people on bikes — in numbers many cities have never seen — take to infrastructure that was not designed for them. If you've ever biked in Portland, or biked through Washington with someone from Portland, it certainly seems as if social norms about traffic laws vary from city to city. Marshall, for example, has observed cyclists in Portland police each other in ways I don't often see in D.C.

But why the differences? As cycling grows more common in a city, does peer pressure to obey the law follow? As cities build more bike infrastructure, does that make cyclists less likely to run red lights?

If some of us violate traffic rules to stay safe, would we be more law-abiding if cities created safer spaces for us? (By this, I do not mean a separate network of biking roads in the woods, but more protected bike lanes and dedicated signals that would allow cars and cyclists to share the road on their way to the same places.)

These questions about sociology and infrastructure point to a more nuanced picture of what's happening on city streets than most heated rhetoric — darn law-breaking bikers! — allows. Marshall, who co-directs the Active Communities Transportation Research Group with Kevin Krizek, wants to research this scofflaw behavior, why people say they do it (drivers and cyclists alike), and when they don't.

As part of this research project, they and Ph.D. student Aaron Johnson and Savannah State's Dan Piatkowski are running a survey that they hope will gather broad data on all of our behavior (go ahead and help science out here, even if you're not a cyclist yourself).

Most of us, whatever mode we travel, break the law at some point, Marshall points out, whether we're driving five miles over the speed limit, or crossing the street against the crosswalk. And yet, we tend not to treat lead-footed drivers with the same disapproval as cyclists who ride through stop signs, even though the former behavior is potentially more publicly harmful than the latter. Which raises another question: Are cyclists really more prolific scofflaws than drivers anyway?

More data on the scofflaws inside all of us could potentially help create safer streets, even, Marshall imagines, more productive public debate about how cars and cyclists coexist. There is some evidence, for instance, that cyclists may be less likely to ride the wrong way down one-way streets and more likely to wait at red lights when they're given dedicated bike paths. This would make sense for a number of reasons.

"You’re treating the bikers well, you’re giving them a place they should be," Marshall says. "You’re giving them respect in the transportation system."

Maybe that makes cyclists more likely to respect the laws of that system in return. Or perhaps, by giving cyclists their own safe space, they don't feel the need to head down one-way streets to bypass busy roads, or to blow through red lights to stay ahead of traffic.

Infrastructure influences how we think about our own roles in public space ("the system isn't looking out for me, so I have to do whatever necessary to look out for myself"). Infrastructure also physically shapes our behavior. On the protected bike lane in front of the Washington Post office, for instance, it's near impossible to run through a red light. That's because bike traffic cues up at the intersection in its own restricted lane the same way cars do.

"You’re putting people on bikes in transportation systems that are entirely built for cars. If that seems to be one of the reasons why people are behaving this way, that would lend an argument to better bike infrastructure," Marshall says. "If people are [being scofflaws] because they like risky behavior, that’s something different. If that’s the answer we find — bicyclists are just riskier than everybody else — that would lead to different solutions."

I'll admit in the back of my own mind that I also sometimes disregard traffic laws not for my personal safety, but because I know that traffic laws, like road infrastructure, weren't created with cyclists in mind. And I say this as a car-owning cyclist, not a culture warrior: It seems somehow unjust — for reasons that Marshall's research may better articulate than me — to expect cyclists to follow all the rules of cars (no turn on red) while denying cyclists the same courtesies (like the right to occupy a full lane).

When you have no radio to turn up, no passengers to talk to, you have a lot of time while commuting on a bike to think about this kind of thing.