> Keep on thumbing Frank, cool stuff! I'm courious how the waiting time goes up with age... :)

It does not have too. This is what you can learn from the stats of Robert Prins. As for me; I'm doing quite the same, but I'm all the time young during the research period. Or would you think it already matters being 24 or 29?

If we do not only look at pick up time, but consider average speed including the waiting time, then we have other relevant factors. In NL the 120 kmh speed limit was introduced 15-20 yrs ago; before it was 100 kmh. Supposedly, the average speed of drivers would increase. On the other hand; the Netherlands faces a mobility overkill (at least from the environmentalists' point of view), which reduces speed of driving.

For inspiration, look at the chart "vitesse moyenne annuelle 1980-1998", which is an analysation of the long term hitchhiking activities of Robert Prins. Check here, about halfway in the document:
http://membres.lycos.fr/bpierret/memoire/memoire.html

On the long run it would be quite easy to bring down average waiting time by choosing the easy routes more often. Eg Luxembourg - Amsterdam or Munchen - Berlin, and by avoiding hard ones like Neuss - Dortmund or Traben Trarbach - Kloden...

F.