Hm. You know, with a heavy luggage load, you've probably got the one situation where staying put downtown is a better idea. I mean, I guess you could walk to Avis, get the car, drive it back up to the Westin to get your luggage, then cart it around with you all day and... but then there's still that issue of whether or not you can return the car at the airport. Eh. Perhaps staying put there is best from a convenience standpoint. Then you pick up and return the car to the same place and don't have to move all that stuff multiple times.
Good luck getting directions from those folks. Maybe I'm just cynical, but I wouldn't be too hopeful.
I guess people working in the travel industry *should* know better, but typical Pittsburghers know their one area of town and that's it.
Surprises me that Avis isn't open until 9, but it might actually save you from trying to go earlier in some heavier traffic. The reality is the routes to the south and east (where you need to go) are heavy enough in both directions both morning and evening rush times. Both interstates (376 east and 279 south) are blocked by tunnels that slow things down. By 9 it should be thinning out, though. Traffic on the way back will be heavy, too, until at least 6ish. But we're talking "heavy" only within a few miles of downtown, coming up to the tunnels.
The "simplest" route I was thinking of (and the one with the least traffic congestion) actually takes I-279 south to I-79 south. And then you just take that down to US 40 east. And that's it. Both Fallingwater and Kentuck Knob are signed off US 40. The only real problem with this routing is it travels for longer distance on a 2-lane road.
The other way would be to take PA 51 south to Uniontown then US 40 east. This would be the shortest distance, no doubt, but the congestion and traffic lights through the south suburbs of Pittsburgh may make this route no shorter time-wise than the previous one. To get to 51 there are a couple of routes, but the easiest may be still to take I-279 south through the tunnel. (I-279 is very easily accessed from Avis, just a right turn out of the garage then a right turn half a block up at the traffic light. Then straight over the bridge and through the tunnel.)
The only other factor here could be the construction they're doing on the section of I-79 just south of I-279. My understanding is it's one side this summer and the other side next summer, so in November they might be done with this year's portion. This is something you can get an update on when you get here, though, then decide which routing you like. There are a couple other route variations, I suppose, but those two are the main ones that make sense. Everything else would be even more out of the way.
One more thing. I'm sure the car reservation probably doesn't matter so much, though you may want to lock it in to have it (no obligation with those guys, normally). But even on a midweek you may want to make sure you get your tour reservations at the Wright houses at the right times of day. I don't know how much they would fill up midweek in November, probably not much, but just in case since you're coming all this way don't wait too long.
That probably about covers most everything, but if you think of anything else (or have other questions about Pittsburgh) please just ask.
