I both bike and drive. I will say, at least in my town, both bicyclists and drivers are egregious traffic violators.

Bicyclists consistently ride on the sidewalk, go the wrong way down a one-way, and run red lights and stop signs. Drivers go way too fast, go the wrong way down a one-way, and run red lights and stop signs.

If bicyclists are going to be on the road, then they need to be licensed. Also, drivers should probably require re-testing when licenses are renewed.