Last weekend, I took a drive on the Pennsylvania Turnpike from Irwin to Somerset, and I've determined that the segment from MM 74 to MM 99 should be relatively easy to expand to six lanes. The interior shoulders have a consistent 10' width on both sides of the median barrier along the entire segment, except for a mile or so on both sides of the New Stanton interchange, where it narrows to 4'. Also, once the segment from MM 99 to MM 109 is finished with its reconstruction and six-lane widening, the only segment with only two lanes eastbound from Irwin to Somerset will be from MM 74 to MM 83. On the other hand, there are only two lanes westbound along the entire segment from MM 74 to MM 99, so that's where most of the work will have to be. Also, about half of the overpasses (six?) on that segment will have to be replaced since they can't fit six lanes underneath. As for the narrower median near the New Stanton interchange, I'm betting that'll be dealt with if there are plans to reconfigure the interchange. Likewise, based on Google Street View east of the Somerset interchange, replacing three overpasses and adding an extra lane in each direction is all that'd be needed once the Allegheny Mountain Tunnel bypass is built, because the interior shoulders are a consistent 10' there as well.