All trucks hauling freight from the Port of Seattle must have engines from 1994 or later, under rules in effect from January 1 of this year.

All drayage trucks – short-haul vehicles that carry goods between ports, docks and rail yards – must now adhere to the port’s Clean Truck Program in order to enter cargo terminals. They must be registered with the port and display a “green gateway” sticker.

Trucks with engines older than model-year 1994 may be eligible for a $5,000 incentive from the Puget Sound Clean Air Agency.

The port said nearly all trucks have complied, and terminals have not had any unusual back-ups since the program debuted.