When biking in traffic or on trails, you can be safer by being visible and riding predictably.  Knowing how to operate your bike's gears and brakes, how to start and stop smoothly, how to check that your bike is ready for your next ride, how to scan for vehicles around you, signal turns and change lanes will reduce the risk when biking in traffic.  Learn more from these League of American Bicyclists Smart Cycling videos.

If you understand how crashes happen, you can avoid those scenarios.  Here are some cases from the Pedestrian and Bicycle Information Center.