Pennsylvania Route 8
| William Flinn Highway | ||||
| Route of PA 8 highlighted in red, and business and truck routes in blue | ||||
| Route information | ||||
| Maintained by PennDOT | ||||
| Length | 148.6 mi (239.1 km) | |||
| Major junctions | ||||
| South end | I-376 / US 22 / US 30 in Wilkinsburg | |||
| 
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| North end | US 20 in Erie | |||
| Location | ||||
| Country | United States | |||
| State | Pennsylvania | |||
| Counties | Allegheny, Butler, Venango, Crawford, Erie | |||
| Highway system | ||||
| 
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Pennsylvania Route 8 (PA 8) is a major 148.6-mile-long (239.1 km) state route in western Pennsylvania. Officially, PA 8 is named the William Flinn Highway.
Its southern terminus is at Interstate 376 (I-376)/U.S. Route 22 (US 22)/US 30 in Pittsburgh. Its northern terminus is US 20 in Erie.