Corridor Business Journal: Just a day and a half after Quad-Citians took their first steps on the new Interstate 74 bridge, motorists are now driving on the Illinois-bound lane. The final span of the new $1 billion, twin-span bridge opened to traffic just after 9 p.m. Thursday evening.  The old I-74 bridge will be permanently closed to traffic because the eastbound green bridge no longer will be needed.