Interstate 70 motorists and truckers crossing the Mississippi River in Saint Louis soon will have a different option.  Missouri and Illinois officials say the new four-lane, cable-stayed bridge will open to traffic February 9, 2014.  The day before, there is a ribbon-cutting and other events scheduled, including letting pedestrians walk out onto the span.  The roughly $700 million project began in 2010, and crews finished connecting the Stan Musial Veterans Memorial Bridge over the river in July.  The span will relieve traffic on the 50-year old Poplar Street Bridge, one of just two in the nation that accommodate three freeways.