When it comes to obeying traffic laws, “we’re all criminals,” says Wesley Marshall, an associate professor of civil engineering at the University of Colorado. Whether it’s driving five miles over the speed limit or breezing past a stop sign on your bike, chances are, we have all broken a few—or more—rules of the road. And after surveying 18,000 people, Marshall is trying to understand why cyclists, in particular, might bend or flat-out flout traffic regulations.