Railroad development in Maine, which reached its peak in 1924, has declined rapidly since World War II, and passenger service has been dropped altogether. Although Maine had no Class I railroads in 2000, nine regional and local railroads operated on 1,202 rail mi (1,934 km) of track.
About three-quarters of all communities and about half the population depend entirely on highway trucking for the overland transportation of freight. In 2000, Maine had 22,670 mi (36,483 km) of public roads. There were 1,052,995 registered motor vehicles and 920,235 licensed drivers in the same year. The Maine Turnpike and I-95, which coincide between Portland and Kittery, are the major highways.
River traffic has been central to the lumber industry; only since World War II has trucking replaced seasonal log drives downstream from timberlands to the mills, a practice that is now outlawed for environmental reasons. Maine has 10 established seaports, with Portland and Searsport being the main depots for overseas shipping. In 2000, Portland harbor handled 29.3 million tons, and Searsport handled 1.4 million tons. Crude oil, fuel oil, and gasoline were the chief commodities. Portland International Jetport is the largest and most active airport in Maine.