I've read that Ascension Thursday (on May 21 in 2009) is a public holiday in Germany, and wonder if that weekend (from Thursday through Saturday) will be a giant traffic jam on the Alpine road, around Bodensee, and Ludwig's castles. Is this a holiday that turns into a 4 day weekend for most Germans, and therefore makes most "holiday areas" a big mess? We may change our route if this is the case.
German ideas of holiday areas are very different than tourist ideas of holiday places. I do not know any Germans who want to go to Ludwigs castles, or Octoberfest, or Rüdesheim, etc. Not to say that there aren't Germans who will go to these places, just that it is not popular with them. With a 4 day vacation, they might just pop down to Turkey, or Spain, some place warm, or go skiing, or believe it or not, fly to New York.
I don't drive over here, so I really don't have a clue about the roads. Trains might be fuller though.
Last year, there was an article posting the top 10 attractions in Germany for Germans and it was interesting to see what they wanted to see in their own country. The top spot, the Cologne cathedral won with just 8.8 % of the vote, so not a "huge" favorite, but just enough.
http://www.thelocal.de/national/20081120-15645.html
We were in Germany for Ascension Thursday in 2001. We were in Berlin, but were leaving to go to Saxon Switzerland on Saturday. We had a really hard time finding a room for Thursday and Friday nights, but when we got there, we found out that was also the weekend of the big national soccer tournament in Berlin.
So, on Thursday, expect for almost all shops to be closed. You may want to see if the sights you want to see will be open. You'll probably also want to make reservations in advance. We also had a hard time finding a room in Saxon Switzerland, since that's an area that Germans go to for short vacations. We walked around the cobbled streets with our rolling suitcase (which doesn't roll very well on cobbled streets) for quite a while before finding the very last available room in town.
I can't testify as to the state of traffic since we took trains.
In Germany, traditionally, Ascension Day (Himmelfahrt) was and is often used by groups and clubs of men as a stag (men only) outing and if it involves a long weekend, then it could become a week-end get-away for guys only, often involving beer, wine and football.
Trains can be packed the Wednesday afternoon before Ascension Day and the Sunday following. Therefore make sure you make a seat reservation (not just a booking, a fixed seat assignment) as early as you can. On days like that, when trains are packed, I find sitting in an compartment to be much more calm and relaxed than on the open plan where people might be standing in the aisles or kids might be running around.
Thanks to those who responded. I guess we will take this into account when making room reservations and deciding on driving routes.