MnDOT operates networks of ramp meters and traffic cameras in the Minneapolis-St. Paul metropolitan area in order to manage traffic flow. The department has also put up informational electronic signage along highways to provide alert messages. Message boards have been in Rochester, Duluth and the Twin Cities for some time. Part of the reason for the Rochester signs is occasional flooding of U.S. Highway 52. The department expanded use of the signs after Amber Alert legislation allocated funding for larger networks. In the Twin Cities, MnDOT began using them to display freeway travel times in 2003 or 2004 to help drivers plan alternate routes to avoid heavy traffic if necessary (although a generic message like "buckle up for safety" is sometimes encountered during special safety campaigns planned in conjuncture with the State Patrol and Department of Public Safety).