The Port Authority of New York and New Jersey plans in mid-February to release details of a clean-air plan that includes a program to replace older trucks. The agency’s director of port commerce would not discuss specifics but said the program will provide port authority funds and federal grants “to support best practices” on emissions from trucks and other port-related sources. … He said the port authority is on track to have its channels dredged to 50 feet by 2014, is improving roadways to smooth the flow of truck traffic, and has begun engineering on an intermodal rail terminal adjacent to Global Marine Terminal in Bayonne, N.J.