I completed an unsupported double crossing of the LHHT. I started on Wednesday night and finished on Friday night [May 1-4, 2013]. My overall time was 50h52m.
I've posted a full report of the effort here:
talesofthetrailturkey.blogspot.com/2013/05/laurel-highlands-hiking-trail-double.html
I wasn’t the first person to take on this challenge. The original double direction LHHT traverse was completed by Art Moore on Memorial Day weekend in 1986. Art started and finished in Ohiopyle and his family provided aid at the road crossings and paced him through the night sections to a smoking fast 35:58:30 finish. Art’s monumental accomplishment was chronicled in an article in the September edition of Ultrarunning Magazine that year. I surmise that a thru-hiker or two have done a double traverse in a traditional backpacking format, but I have not found any documented accounts other than Art’s.