Allegheny County belt system

Allegheny County Belt System
Static map of Allegheny County with the system   Red Belt   Orange Belt   Yellow Belt   Green Belt   Blue Belt   Purple Belt   (River)
System information
Maintained by ACDPW, PennDOT and city agencies
Length	280.5 mi (451.4 km)
Highway names
Interstates	Interstate nn (I-nn)
US Highways	U.S. Route nn (US nn)
State	Pennsylvania Route nn (PA nn)

The Allegheny County Belt System color codes various county roads to form a unique system of routes in Allegheny County, Pennsylvania, and around the city of Pittsburgh.

Unlike many major American cities with belt systems composed of number-coded limited-access roads, the Allegheny County Belt System roads are not intended to be used as high-speed routes. Rather, the system is a navigational aid for motorists in unfamiliar portions of the county.^[1] Five routes were introduced in the early 1950s: from outermost to innermost, the Red, Orange, Yellow, Green, and Blue Belts. The Purple Belt was added later. All roads in the system retain their original names.