The cost of renting a car at Los Angeles International Airport could soon go up. Airport managers want a big, new building to bring all rental agencies together under one roof. And somebody has to pay for it. Airport commissioners are scheduled to vote Monday on a $10 surcharge for every car rental at LAX. The money would help fund a long-standing plan to curb traffic and cut pollution by herding car-rental firms into a single location. The move would eliminate the need for each of the companies to operate its own fleet of shuttle buses. Currently, rental-car companies scattered around the airport account for an estimated 800,000 shuttle trips a year. The center is a “vital step toward the alleviation of congestion” at the airport, according to a staff report prepared for commissioners. It would give travelers a single place to get a car and a single shuttle route to get there. That, the report noted, would reduce the number of shuttle buses spewing exhaust into the air. Airport officials have estimated it would cost as much as $800 million to build the rental center. A year could be required before construction begins, but the $10 surcharge per rental could come as early as May. “This facility is inevitable,” commission President Alan Rothenberg said at a meeting last month. “The sooner we can accomplish it, the better.” email@example.com (310) 543-6649 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! Rental companies, however, have dug in for a fight, saying they have yet to see plans or justifications for the center. “We don’t think it’s legal,” said Richard Broome, vice president of corporate affairs for The Hertz Corp. “We are absolutely flabbergasted that the airport would move ahead without any idea of how the facility is going to be paid for or what it’s going to look like.” The new building would replace an old parking lot just east of the airport. It would bring together 26,000 parking spaces in all, as well as offices for the main rental companies that currently operate at LAX.