Tammy Duckworth, Sherrod Brown and Bob Casey introduce new bill to make public transit more accessible

Nearly 20% of all transit stations in the U.S. aren't accessible to people with disabilities and don't fully comply with the Americans with Disabilities act, according to the Federal Transit Administration. It's a problem Senator Tammy Duckworth, Democrat of Illinois, says she knows too well.

"Oh my goodness, yes. I tried accessing the subway in New York once and could not get on because the elevator wasn't not working, and the next one didn't have an elevator — or the one after that," she said in an interview with CBS News this week. "In Chicago, I can't get into some stations because it's three flights of stairs to get to stations." Duckworth, who is a double amputee, uses a wheelchair.  She lost her legs in 2004 when the U.S. Army helicopter she was flying was hit by a rocket propelled grenade in Iraq.