A coalition that includes the Sierra Club, the Brooklyn Chamber of Commerce, and the Abyssinian Baptist Church is backing a project to build a new tunnel under New York Harbor to reduce truck traffic in the city. The proposed rail freight tunnel would divert almost a million truck-trips per year away from the George Washington Bridge; it is supported by business, labor, environmental, and civic leaders, who say it will ease traffic snarls, reduce pollution in neighborhoods suffering from high asthma rates, generate jobs, save money on road maintenance, and even curtail terrorism by limiting the threat of truck bombs. Critics counter that most of the freight would still be moved by truck once it entered the city, and that few of the kinds of industries inclined to take advantage of rail freight do much business in New York City. Currently, less than 2 percent of all freight moving in and out of the area is transported by rail, compared with the nationwide average for cities of 40 percent.