The board did not say how much equipment might be needed or how much getting extra trains will cost.
Meanwhile, the city is polishing its pitch for the games. "Let friendship shine," was the new slogan introduced Sunday by the Olympic bid committee. It will be used in all ads and videos promoting Chicago's bid. The new slogan replaces "Stir the soul," which has been used since Chicago was named the U.S. candidate city more than one year ago.
