Blue Belt (Pittsburgh)

Allegheny County Belt System
Map of Pittsburgh 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 miscellaneous county roads to form a unique system of routes in Allegheny County, Pennsylvania, and around the city of Pittsburgh.

Unlike many major American cities that utilize number-coded limited-access roads to form belt systems, the belts in the Allegheny County Belt System are not intended to be used as high-speed routes. Rather, the belt system is to be used as a navigational aid for motorists in unfamiliar portions of the county. Roads that make up the Belt System retain their previous names. The five original routes are, from outermost to innermost, the Red, Orange, Yellow, Green, and Blue Belts. The Purple Belt was not part of the original system and was added later.

The Allegheny County Belt System was developed in the late 1940s by Joseph White, an engineer with the Allegheny County Department of Public Works, as a wayfarer system using a network of federal, state, and municipal roads to offer residents alternative traffic patterns which did not lead to downtown Pittsburgh's congested Golden Triangle. As such, it actually predates the Interstate Highway System developed during the Eisenhower administration.

From late 1951 to early 1952, the signs were posted throughout the finalized belt routes, starting with the Orange route, then Blue, Yellow, Red and Green.

The belt routes were not intended as high speed or limited access roads, but instead as a well-defined road system away from the existing major arterials and their congestion.

The construction of the interstate highway system and regional parkways during the late 1950s through the early 1970s initially reduced the use and need of the belt routes. As urbanization of the county spread further out from the City of Pittsburgh, however, the Belt System helped to reduce the effects of suburban congestion. Many of the roads selected over fifty years ago today play key roles in the long-range regional transportation plans of Allegheny County. Many of the roads chosen for the belts have been converted from simple country lanes to urban collector roads and to urban arterials.

In its millennium edition, Pittsburgh Magazine (published by WQED television) recognized White as one of the one hundred most influential people of the 20th century in the Pittsburgh region. Rick Sebak from WQED television also produced a local feature on the Allegheny County Belt System in the 1990s.