Pennsylvania State Route 531 is a short north-south highway in Northeastern Erie County. It runs from U.S. Rt. 20 to Pennsylvania State Route 430. PA St Rt 531 does not pass through any towns in Erie County. PA St Rt 531 is multi-plexed in Erie County. PA St Rt 531 intersects the following highways in Erie County. U.S. Rt. 20, near Harborcreek. Interstate 90, near Harborcreek. Pennsylvania State Route 430, near Hammett.