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Phase II - Allegheny Tunnel Traffic Relief Study

Preliminary tunnel improvement study including alignment and tunnel design
Estimated cost: Commencement:
February 28, 1998
Completion date:
December 30, 1998
Allegheny, PA
United States
Technical data:

Preliminary alignment study looking at four new tunnel options and rehabilitation of the existing tunnels. Design of two to four lane highway tunnels up to 6100 ft (1860 m) in length supported with rockbolts, reinforced shotcrete and lattice griders.

Geology description:

Interbedded Shales and Sandstones with Limestone interbeds, Coal and Claystones. Decomposed to highly weathered fractured rock at the tunnel portals.

Geology types:
Service areas:
Plan showing the existing topography, roads and streams along with the four Alignment Options
Profile showing the existing topography along the Red Alignment Option - Westbound Tunnel