I will personally be doing the trip in 2014. I decided many factors of the way im going. Im gonna do it west to east. Starting in Astoria,OR and finishing in VA. Approx mileage 4,200 miles. 2 of my main reasons i choose west to east was the wind direction for the most part goes west to east or some what that way vs going east to west where you might have the wind in your face more. 2nd being getting the worst of the mountains out of the way towards the beg of your trip. Whatever way you choose hope all is well and good luck .
I read that all the time and in my experience this bias toward W-E based on wind direction is just not true for the Trans America. Prevailing westerlies do not necessarily equate to prevailing surface winds in that direction. It may be true for the Northern Tier and I suspect it might be close to a wash for the ST, but it probably depends on when you go. I never looked very closely at the wind maps for the ST in different months though so I may be wrong on that.
We went West to East on the TA and did not regret it. There are many advantages/disadvantages either way you choose. That said I found that the winds did NOT favor that direction of travel. The maps below seem to match our experiences for the trip perfectly. If winds are your primary criteria for the Trans America then going East to West
is better. That said I would not make the decision based exclusively on wind direction.
If you look at these maps you will see that in the parts of the country where the winds really matter (the plains) the summer winds favor E-W travel on the TA.
We chose W-E for a number of reasons, but if surface winds are your primary concern and
you will be on the AC Trans America Route I would go E-W.