First, I think it is crazy that people have posted reviews about a tunnel, but since I saw them, I figured I mine as well add my comments.
I think the traffic engineer who designed the tunnel didn't live in reality because too many lanes of traffic merge and there are always back ups. What they did get right was creating a real entrance to the city.
I joked that they should post a warning sign in the tunnel for unsuspecting motorists that says something like "warning: the end of this tunnel opens to a remarkable view of the downtown Pittsburgh" Or maybe part of what makes it so special is the surprise element.
Whether you are entering the city for the first time or you are on your way home, you get an exquisite view that almost makes waiting in the inevitable traffic worth it.