The Bush administration on Monday announced a proposal to implement a congestion pricing plan at congested U.S. airports. Under the proposal, airlines would have to pay more to use departure/arrival slots during peak travel hours.The "surprising move" by the U.S. Transportation Department, according to Reuters, comes after months of weighing options for airlines to voluntarily smooth out flight schedules and streamline air traffic operations in New York and other key cities.Major carriers oppose congestion pricing as they face higher fuel costs, and other pressures on their slim profit margin. Carriers blame an outdated air traffic control system for rampant delays this year, the second worst year of performance by domestic airlines on record since the government began collecting such data in 1995. The proposal must now undergo a six-week public comment period, and if passed would move airports away from the decades-old practice of charging landing fees based on aircraft weight. Instead, airports would have the flexibility to vary charges based on the time of day and the volume of traffic, according to Reuters.Air authorities said the plan would allow airports to even out traffic and allow airports to handle more passengers. Airlines have been criticized for over-scheduling flights during peak hours. A flight cap limiting the number of scheduled flights at New York's John F. Kennedy Airport is already being implemented in attempt to reduce delays.