Factors contributing to the rise of U.S. freight railroads since about 1980 are _________.A) road congestion, concerns about pollution and noise, and development of the multi-modal container.
B) higher train speeds, development of more custom service by railroads, and concerns about terrorism.
C) increased shipments of high-value goods like computers, unreliability of air freight, and the building of new railroads.
D) All of the above
E) None of the above

As more cars and trucks flood the roads, the more expensive it is to transport cargo on roads. The main advantage of freight railroads are its much lower costs and even though most US cargo trains run on diesel engines, they still pollute much less than big trucks. A train diesel engine does pollute a lot, but if you divide pollution by the massive amounts of cargo it transports, the environmental equation is extremely favorable. Trains are extremely noisy, but they do not travel near homes and when they do, it is just for a few minutes. Therefore the noise doesn't bother residential areas.