From the Frankfurt and Stuttgart airports, there's fast and easy access, by car and train, to all major centers along the Neckar.
With advance reservations you can get to Heidelberg from the Frankfurt airport via the shuttle service TLS. The trip takes about an hour and costs EUR 29 per person; with four people, EUR 22.25 each. No reservations are needed for the Lufthansa Airport Bus, which is not restricted to Lufthansa passengers. Service is daily, on the hour, 8-1, 3-7, and 10 or 11 PM. It departs from Frankfurt airport, Terminal One, Hall B, arrivals level. Exit at B-4, close to the Treffpunkt (Meeting Point), to reach the bus stop. The trip ends at the Crowne Plaza Hotel in Heidelberg and costs EUR 19 per person.
Heidelberg is a 15-minute drive (10 km [6 mi]) on A-656 from Mannheim, a major junction of the autobahn system. Heilbronn is near the east-west A-6 and the north-south A-81. The Burgenstrasse (Route B-37) follows the north bank of the Neckar River from Heidelberg to Mosbach, from which it continues south to Heilbronn as B-27, the road parallel to and predating the autobahn (A-81). B-27 still leads to Stuttgart and Tübingen.
Western Germany's most important rail junction is in nearby Mannheim, with hourly InterCity trains from all major German cities. Heidelberg is equally easy to get to. The super-high-speed InterCity Express service, which reaches 280 kph (174 mph), is Germany's fastest. Travel time between Frankfurt and Stuttgart is less than 1½ hours; between Heidelberg and Stuttgart, 26 minutes. There are express trains to Heilbronn from Heidelberg and Stuttgart and direct trains from Stuttgart to Tübingen. Local services link many of the smaller towns.
Lufthansa Airport Bus (0180/583-8426 in Heidelberg. www.lufthansa-airportbus.com). TLS (06221/770-077. www.tls-heidelberg.de).
State Tourist Board BW (Esslingerstr. 8, D-70182, Stuttgart. 0711/238580. www.tourismus-bw.de). Die Burgenstrasse (Allee 28, D-74072, Heilbronn. 07131/564-028. www.burgenstrasse.de).