Germany - Switzerland - Alsace road trip:

You have a comparably short trip, which is prone to make it a bit of a hassle.
How important is specifically Rothenburg to you? Would it be possible to fly into Zurich instead? It is an established hub, and possibly more convenient. You could just hop on a train and pick a car in German Konstanz if necessary to avoid fees, and fly out of Frankfurt as planned.

For context: Nice Timberframe constructions can be found elsewhere along to „main part“ of the trip.

You have a comparably short trip, which is prone to make it a bit of a hassle.
How important is specifically Rothenburg to you? Would it be possible to fly into Zurich instead? It is an established hub, and possibly more convenient. You could just hop on a train and pick a car in German Konstanz if necessary to avoid fees, and fly out of Frankfurt as planned.
For context: Nice Timberframe constructions can be found elsewhere along to „main part“ of the trip.

I agree the trip is short, so it naturally turns into more of a "road trip" than an ideal slow-paced visit 🙂

Because of how we booked our flights using points and the convenience of returning the car and luggage at the same airport, Frankfurt works best for us for both arrival and departure.

Rothenburg is something we are currently considering based on strong recommendations and photos I have seen in photography forums, but it is not set in stone. If there is a better or more suitable alternative that fits the route and offers a comparable or stronger experience, I would be very happy to consider it.

Day 4 - how will you route to Colmar? I'd use the excellent Swiss highways to Basel, possily enjoying the Rheinfeldens (CH&D) on the way, then straight up.

Or you may retrace you way back into Germany and go through the woods to the Rhine crossing between Freiburg im Breisgau and Colmar.

The second would be much slower and more work.

If you do the first, if you have avoided any Swiss highways in what you laid down, you will almost certainly use them towards the west. That means you will need a Swiss highway Vignette which costs CHF 40 for a calendar year even though you only need one day..

I actually really like it. Rothenburg, Rhine Falls and Stein am Rhein stretch is long but rewarding. Between Stein am Rhein and Colmar I’d lean into arrival in Colmar rather than adding more stops. Day 5 doesn’t feel too light to me.

Day 4 - how will you route to Colmar? I'd use the excellent Swiss highways to Basel, possily enjoying the Rheinfeldens (CH&D) on the way, then straight up.

Thanks for pointing that out, that’s exactly the decision I am weighing.

I am aware that using Swiss motorways toward Basel would require purchasing the CHF 40 vignette, even for a short use. We are fine either buying it for the convenience, or deliberately avoiding Swiss highways and routing back through Germany via the Black Forest and crossing near Freiburg.

Since this is our only day in Switzerland, we will decide based on how we are feeling that morning, efficiency via Basel with the vignette, or a slower but scenic German route if we skip it. Appreciate the clarification.

Mid -June? Forget Rothenberg, go to Konstanz. From there you can drive around the lake, see Mainau, Meersburg, Lindau, etc. And it's a fairly short drive over to the Rhine Falls also, so you can do this en route to the Alsace.

My choice of how to move north from Colmar is dependent on what I want to do. I drive those roads fairly often. It's a very short trip by autobahn from Colmar to Heidelberg, with the worst traffic being around Stuttgart. And honestly, if you want to traverse the Black Forest you'd be better off starting from Freiberg.

The route from Freiberg to Pforzheim is okay, staying mostly on A 294, and you'll pass through some small towns worthy of a stop and stretch of the legs (even better do this on a Saturday morning when the local markets are running until 1300.) I recommend this if you have any interest in visiting Kloster Matchern, which is fantastic. Pforzheim is also worth a visit if you have any interest in watches, clocks, or jewelry, as 80% of the watch and clock movements from Germany originate in this city. This is where to go for your cuckoo clock, not some tourist destination.

The drive from Colmar to Freudenstadt, to pick up A500 is a pain. And frankly it's not worth it. Driving 500 in June, when every other car will be towing a caravan, is not my idea of fun. And while Baden-Baden is a nice city (I was there, again, just two weeks ago) it's also annoying to traverse.

Route 3, or A5 which it parallels, is the fastest way north, but it's not what I consider scenic.

If you want a scenic route, head (from Colmar) to Hagenau, then to Wisembourg and Bad Bergzabern, From there go to Annweiler, Edenkoben, Neustadt, Bad Durkheim and then (on 650) to Heidelberg. On this route you'll pass over a dozen castles, towns that specialize in pottery, a couple places where you can walk the WWII fortifications or detour to see the Maginot Line forts, some very attractive small towns, a couple hundred vineyards, really pretty scenery, and a couple medieval walled towns that I prefer to the tourist destination of Rothenberg. Stay off A65 for the best drive.

I would second KCG in considering Konstanz or particularly Meersburg over Rothenburg in June, which is why I had asked about Zurich as well - you will spend much of your first or second day driving if you start in Frankfurt (Rothenburg-Schaffhausen or Frankfurt-Meersburg are both about four hours nonstop). If you do not mind that or have booked flights already, sure - it is definitely doable. I live near Frankfurt and have family near lake Constance, so we do the trip twice a year.
If you are going straight south, you could stop in Pforzheim for lunch, or Ludwigsburg (depending on the route), each would split the trip nicely in two (more or less).
Another idea would be
1. Frankfurt arrival
2. Heidelberg, overnight there or a bit south (again Ludwigsburg for example)
3. Meersburg/Konstanz
4. Basel/Rheinfelden or Black Forest in the Freiburg/Titisee/Schluchsee region (depends what you prefer)
5. Colmar
6. Wissembourg, visit Strasbourg or Alsace towns and castles on the way
7. Wissembourg to Frankfurt is only slightly longer than Heidelberg to Frankfurt

It might be a bit more convenient that way. Stops are more equally spread out. It also might give you the opportunity to choose country roads over highways more conveniently - those 4-hour-trips are highway only, and the Autobahn is rarely scenic.

This makes a lot of sense, especially the point about Autobahn-heavy days not being scenic. We are comfortable with driving but would rather avoid long “dead” stretches. The Heidelberg --> Lake Constance --> Freiburg --? Colmar flow looks much more evenly paced.

We’ll re-evaluate whether Rothenburg is worth the extra push in June, and consider Meersburg/Konstanz instead. Thanks for the practical perspective, very helpful.

If you go via Pforzheim detour and see Kloster Matchern. If you go via Ludwigsburg visit the Schloss; the gardens in June are really something (it was built to outdo Versailles).