Ohio Department of Transportation, January 1, 2005 Straight Line Diagrams Archived February 19, 2003, at the Wayback Machine Approximated from Mapquest "Pennsylvania Highways: US 30".
2014년 10월 9일에 확인함.  Ohio Department of Transportation, January 1, 2005 Straight Line Diagrams Archived 2003년 2월 19일 - 웨이백 머신 Approximated from Mapquest “Pennsylvania Highways: US 30”.