Community leaders in Chicago visited O'Hare International Airport on Tuesday for a primer on the importance of NextGen. Rep. Dan Lipinski, D-Ill., helped make the case that new construction can only go so far in reducing delays as long as the airport is hampered by an antiquated air-traffic control system. "We have GPS in many of our cars to drive down the road. It only makes sense that we use that for aviation also," he said. Later this year, Chicago airports are due to implement several stopgap measures dubbed NowGen, but experts say only a full NextGen rollout will avoid gridlock as U.S. air travel climbs to an estimated 1 billion passengers annually by 2025.