Hatched in the 1950s, the Romantic Road is a touristic brainstorm that rather arbitrarily strings together some very quaint and picturesque towns in the southern half of Germany.
The route begins in Würzburg and winds its way 215 miles south to Füssen, home of Neuschwanstein, Mad Ludwig's castle of Disneyland fame. Rothenburg ob der Tauber is certainly the best known stop along the way, but many of the other towns and villages are also interesting and attractive, particularly Dinkelsbuhl and Nördlingen. Much of the countryside along the route isn't particularly noteworthy, however.
Unfortunately there's no train that follows the 'Romantische Strasse' but there is daily bus service designed specifically for tourists Europabus #190 between Würzburg and Munich and #190A connecting Rothenburg and Füssen. The former takes just under eleven hours, the latter about six. Both include a 1-1/2 hour layover in Rothenburg for sight-seeing purposes. The trip is included on Eurailpass and all German Rail Passes. Space is limited and reservations are highly recommended.
For most people, renting a car is the best solution. They are then free to spend three or four days exploring the Romantic Road in a leisurely manner and timing their stops to avoid crowds at the most popular spots.
An interesting and recent development in the historic road department: one Japanese tourist was so impressed with the financial advantages to towns along Germany's Romantic Road that he decided to create one in his own country. There is now an elaborate scheme in place that has Japanese citizens rushing up and down the romantic roads of both countries, collecting stickers along the way as proof of visitation. It's called a 'visual sticker rally' and successful participants not only receive a certificate of completion but a chance to participate in a lottery for grand prizes. Signs marking Germany's Romantic Road are in German and Japanese.