by PennDOT,. As of 2022, the route is still signed. Previously there was a truck route in the Pittsburgh suburb of Elizabeth. The truck designation was not intended for vehicles already on PA 51, but for those entering the highway southbound. A cloverleaf has been established to direct traffic between Elizabeth's main street (known as Center Ave and McKeesport Road on different ends of town), but its narrow and winding design makes it difficult for trucks to access Route 51 southbound. As a result, they were directed to enter onto Route 51 northbound, cross the bridge over the Monongahela River, and use a special u-turn exit to reach southbound lanes of travel. This truck route was removed after a weight limit was imposed on the Regis R. Malady Bridge over the Monongahela River. See also References External links Pennsylvania Highways: PA 51 Route 51 history 051 Transportation in Pittsburgh Transportation in Allegheny County, Pennsylvania Transportation in Fayette County, Pennsylvania Transportation in Westmoreland County, Pennsylvania Transportation in Beaver County, Pennsylvania