Driving from Amsterdam to Switzerland, Via Germany?

Knowing the traffic in the Netherlands, it would probably take far longer than 8 hours to drive to Lucerne... but I digress...

Yes, a 3 to 4 day driving trek would be very reasonable, although you'll pay extra to pick up and drop off a rental car in different countries. Depending on the company, the length of time you rent and which countries involved, the fee could be minimal to significant. Another factor to consider is the price of fuel, which is far more expensive than in the US. As to how this would compare to riding trains in terms of cost? Difficult to say, unless we knew where you planned to stop. By the way, there is no "Eurail". That's just the name of an agency that sells tickets to travelers for the various European national rail companies.

With 4 passengers, it might indeed be more economical to drive than to go by rail. I would price out both ways. You can get current gas prices in Europe easily. I would use viamichelin.com to get a variety of routes and distances. It also gives fuel costs, but I do not know how often they update this information. With that said, try not to drive from Amsterdam to Germany on a weekend or particularly on a holiday. Traffic can be horrendous. I was in Siegen for school some (cough, cough) 20 odd years ago and a group of us rented a car one weekend to go to Amsterdam. The day we returned was the end of a big holiday and it took us 5 hours to make what had been a 1.5 hour trip going the other direction only two days before. Places I would hit along the way between Amsterdam and Luzern: Koln, Heidelberg and Strasbourg or Colmar in France. However, I would be inclined to take more than 3 or 4 days for this trip if I wanted to really see some of them.

There are two German freeways that range from the Dutch to the Swiss (respectively French) border. One is via Düsseldorf, Limburg, Frankfurt, Heidelberg, Freiburg and Basel, the other is via Cologne, Koblenz (Mosel river valley), Mainz (Rhine river gorge), Alsace to Basel. Both are euqally as long but pass very differnt kinds of sights...

"With that said, try not to drive from Amsterdam to Germany on a weekend or particularly on a holiday."

An addition to that statement. Traffic in the Netherlands is ALWAYS bad, but probably worse during the work week. Imagine Chicago commuter traffic (Amsterdam), now put several cities the size of Baltimore within 100 miles of it (Den Hague, Rotterdam, Leiden, Nijmegen, Arnhem, Utrecht, etc.) and you get the idea.

I have generally found that outside the major metropolitan areas in Europe, traffic is pleasently light. The Netherlands is the one glaring exception.

Thanks for all the help. I think we are just going to stick with the train. :) Since the main aim is to see Swiss vs. Germany.