U.S. Federal Route 40 is the main east-west expressway through Central St. Louis. This highway runs from the Poplar Street Bridge at downtown to the central-westend and into West County. Over the past 15 year Interstate 64 has been extened along this route. Now I-64 is shieled with U.S. Rt. 40 through out St. Louis. Near downtown, U.S. Rt. 40 turns into a double deck highway. WB traffic on the upper level, and EB on the bottom. U.S. Rt. 40 is multi-plexed in St. Louis. Interstate 55, from the Illinois/Missouri State Line for less than a 1/4 mile. Interstate 64, from the Illinois/Missouri State Line to the St. Louis/Richmond Heights City Limits.