The Federal Highway Administration on Monday gave its final approval for New York City’s congestion pricing plan—which would charge drivers to enter midtown Manhattan in an attempt to reduce both traffic and pollution. The approval marks the plan’s final federal hurdle, and means the system will almost surely go into effect as soon as next year, according to The New York Times. It’s unclear how much the Metropolitan Transit Authority (MTA) toll to enter Manhattan south of 60th Street might be, but some estimates released by the agency ran as high as $23 during rush hour and $17 during non-peak hours.