So many Americans are overweight that the Federal Transit Authority is proposing to rewrite bus-safety rules because of it. The agency proposes raising the assumed average weight per bus passenger from 150 pounds to 175 pounds - which could mean fewer people will be allowed to ride buses around the country. The changes "acknowledge the expanding girth of the average passenger," the agency says. "This change is really just a bow to reality," says Joseph Schwieterman, who studies bus ridership as director of the Chaddick Institute for Metropolitan Development at DePaul University. "With no small number of bus passengers tipping the scale at 200 pounds or more, this is much more realistic." Gannett News Service