With summer just around the corner and visions of vacations dominating Americans' thoughts, our highways will experience a dramatic increase in traffic. To enhance the travel experience for motorists, the National Motorists Association (NMA) has designated June as Lane Courtesy Month and is kicking off the campaign with the slogan "Do the RIGHT Thing!" Lane Courtesy, also called Lane Discipline, has a powerful influence on highway safety, traffic flow, and congestion. Arguably, its effect is more important than speed limits, traffic enforcement, or any other attempt to control driver behavior. Ask almost any motorist what most raises their ire when...