Coming from Hamburg, take the A7 motorway. Near Hanover, take the A352 towards Dortmund/Hanover-Nord/Airport to the A2. Continue to the Autobahnkreuz Bielefeld interchange and take the A33 towards Paderborn. At the Autobahnkreuz Wünneberg-Haaren interchange, take the A44 towards Kassel. Take the Diemelstadt exit and continue on road B252 to Bad Arolsen.

Coming from Frankfurt take the A5 motorway to the Gambacher Kreuz interchange. Continue on the A45 towards Köln/Dortmund/Wetzlar/Marburg/Gießen. At the Gießener Südkreuz interchange, take the A485 towards Marburg/Gießen/Linden. Then continue on road B3 just after Cölbe towards Frankenberg. In Korbach, take road B252 to Bad Arolsen.

Coming from Leipzig take the A38 motorway. Near Kassel, take the A7 and the immediately take the exit for the A44 towards Dortmund. Continue to the Bad Arolsen-Breuna exit, then take road L380 through Volkmarsen to Bad Arolsen.

Coming from Duisburg take the A40 motorway. Continue on road B1 and then the A44 to exit 64 in Diemelstadt. Then continue on road B252 towards Korbach/Twistesee to Bad Arolsen.

From the well-connected ICE train station in Kassel-Wilhelmshöhe, take the regional train to Bad Arolsen station. The journey takes about 1 hour.
  
Use the following link to the Deutsche Bahn website to plan your trip:

The Flixbus long-distance coaches travel throughout Germany and neighbouring countries. They provide an eco-friendly, low-cost option for travelling to Bad Arolsen.

To see their timetables and stops, follow this link: