While clean trucks were a focus, the Port of Long Beach also turned its attention to ships. The Green Flag incentive program was set up to encourage ships to slow down in order to improve air quality. The Green Flag program provides approximately $2 million a year in discounts for vessel operators who slow their ships to 12 knots (22 km/h) or less within of the harbor. According to the port, the Green Flag program reduced air pollution by 600 tons in 2007 and was expected to do better in 2008.