TRANSPORTATIONThe nation's busiest airports could be forced to close some of their runways, causing widespread flight delays and cancellations. Transportation Secretary Ray LaHood predicts flights to cities like New York, Chicago and San Francisco could have delays of up to 90 minutes during peak hours because fewer controllers will be on duty. Though the spending cuts are scheduled to go into effect on Friday, furloughs of controllers won't kick in until April because the Federal Aviation Administration is required by law to give its employees advance notice. In addition to furloughs, the FAA is planning to eliminate midnight shifts for air traffic controllers at 60 airport towers, close over 100 control towers at smaller airports and reduce preventative maintenance of equipment. NATIONAL PARKS Visiting hours at all 398 national parks are likely to be cut and sensitive areas would be blocked off to the public. Thousands of seasonal workers looking for jobs would not be hired, according to Interior Secretary Ken Salazar. Salazar and National Park Service director Jon Jarvis said visitors would encounter locked restrooms, fewer rangers and trash cans emptied less frequently. FEDERAL WORKERS More than half of the nation's 2.1 million government workers may be required to take furloughs if agencies are forced to trim budgets. At the Pentagon alone that could mean 800,000 civilian workers would be off for 22 days each, spread across more than five months â¿¿ and lose 20 percent of their pay over that period. Other federal agencies are likely to furlough several hundred thousand more workers. EDUCATION Some 70,000 students enrolled in pre-kindergarten Head Start would be cut from the program and 14,000 teachers would lose their jobs. For students with special needs, the cuts would eliminate some 7,200 teachers and aides. The Education Department is also warning that the cuts will impact up to 29 million student loan borrowers and that some lenders may have to lay off staff or even close. Some of the 15 million college students who receive grants or work-study assignments at some 6,000 colleges would also see changes.