Penn Pike revives idea of cut in place of Allegheny Mtn tunnels - study RFP

Pennsylvania Turnpike Commission will be issuing an RFP shortly for a planning study of the future of their Allegheny Mountain tunnels. Two 2-lane tubes 1850m long they date back to 1940 and 1965. A study of alternatives in the 1990s concluded the tunnels should be abandoned in favor of a 67m (220ft) deep cut to the north of the tunnels. The cut plus 4500m (2.8 miles) of new approach roadway was 40% less capital cost than twin 3-lane tubes with a shoulder.

Tunnels have higher operating costs than a cut.

Average daily traffic - 31k/day - doesn't require a third lane. However summer peaks and growth in average traffic could justify the additional capacity (and a peak toll rate.) The third lane is also helpful in maintaining capacity during repaving. It would also conform to the 3+3 lanes being built along the length of the highway as part of full reconstruction.

The present tunnels are in good structural shape but there is some water seepage. Icicles form inside the tunnels in winter requiring tunnel closures for workers to remove them before they become a safety hazard.

Hazardous materials vehicles are not allowed in tunnels and presently get directed off the Turnpike for nearly 60km (36 miles) on US30 Lincoln Highway and PA281, surface roads through the middle of Somerset and Bedford townships.

The original Turnpike had a 2067m (6782ft) Sideling Hill Tunnel even longer tunnel than Allegheny Mountain tunnel, but this was eliminated with a cut in 1968.

Last time the Allegheny Mountain relocation and cut was proposed a hunting/fishing/wildlife group which would lose land to the new Turnpike location successfully blocked it. Therefore the new study may need to find ways to "mitigating wilderness impacts" or whatever.

The Allegheny Tunnel is located between Interchanges 110 and 146 in the Turnpike's central region. The Turnpike here is co-signed I-70/I-76.

TOLLROADSnews 2009-05-31