Find a map of Pittsburgh and spread it out upon the table. Make it a good map, detailed enough to show all of the actual streets downtown and surrounding, perhaps even the paper ones that fly off into space above the rivers or worm their old ways under newer steel and stone. Put your finger on the Monongahela river where it reforms itself into half of the Ohio. Begin to drag it east, up the channel. Put ripples in the water with your nail past the Fort Pitt bridge, past the Smithfield Street Bridge, past the little train bridge that carries the T and holds a name that no one remembers (Panhandle Railroad Bridge). Let your finger feel the draw of that mighty river, navigable in entire, and keep pushing east.
Stop at that next bridge running over the river, and investigate. This is the Liberty Bridge, carrying cars to and from the Liberty Tubes (tunnels) to the south and a tangled mess of road and ramp to the north, which I will not attempt to explain, even with the help of the map. Put your finger on the bridge, now, and trace it south (please remain in the western lanes) to where the roadway runs to tunnel and dips beneath Mount Washington.
Do not enter the tunnel with your finger; it is not likely to fit, and trouble in the tunnels snarls traffic for miles upon miles. Even if your finger fit, you would be forced by local custom to slow to ten miles per hour, and after five minutes of following that dotted line on the map on the coffee table your back will begin to hurt. Instead, at the southern end of the bridge, turn west. This will also be a turning upward, as you are now scouring a nail-plowed furrow in the surface of McArdle Roadway.
This road climbs as it clings to the side of Mount Washington, offering access to the oohs and aahs of the downtown Pittsburgh view at the top. It is worth the trip up it to walk along the top of Mount Washington, taking in sights and looking down on birds. I would recommend to take your finger there on a summer afternoon when the hillside trees are in full leaf, driving up the roadway and moving through a corridor of green and outcrop, with occasional view of the deepening city peeking through from the right.
Over this road passes one of Pittsburgh’s two working Funiculars, the Monongahela Incline, on a steep thin track just below the tops of trees. If you are lucky on the way up, you will pass beneath the trackway just as one of the Incline’s cars rumbles by above, going upways or down. It will spill into the space over the roadway as an invader, intruding from bygone years, an incongruity made more so by the quickness of its passing from view. You may see people on it, and they may see you, but there is no time to wave; a curt nod is what is possible, and all that is really required.
This trick does not work as well on the way down McArdle; I do not know why. This, also, is not a thing that can be planned. It happens or it does not. The only remaining difficulty is that your finger, heavy and massive and huge from the sky, would easily snap the tracks in two, should it try to pass there.
I say: take a car instead, and good luck.