The TSA is making the first significant changes to airport checkpoint screening since the 1970s as part of an effort to make screening calmer and more relaxed for travelers. It is testing the changes at Baltimore-Washington International Thurgood Marshall Airport, where mauve lights, soothing music and smiling employees will greet passengers. "A chaotic, noisy, congested checkpoint is a security nightmare. Chaos gives camouflage," TSA Chief Kip Hawley said. "A chaotic environment puts subtle pressure on (screeners) to rush the job."