| Radolfzell am Bodensee to Smolyan | 879.97 mi (1,416.17 km) |
| Radolfzell am Bodensee to Sofia | 779.16 mi (1,253.94 km) |
| Radolfzell am Bodensee to Sopot | 842.94 mi (1,356.58 km) |
| Radolfzell am Bodensee to Sozopol | 981.97 mi (1,580.32 km) |
| Radolfzell am Bodensee to Sredets | 961.79 mi (1,547.85 km) |
| Radolfzell am Bodensee to Stamboliyski | 851.96 mi (1,371.10 km) |
| Radolfzell am Bodensee to Stara Zagora | 890.10 mi (1,432.48 km) |
| Radolfzell am Bodensee to Svilengrad | 937.97 mi (1,509.52 km) |
| Radolfzell am Bodensee to Svishtov | 838.56 mi (1,349.54 km) |
| Radolfzell am Bodensee to Targovishte | 905.30 mi (1,456.94 km) |
| Radolfzell am Bodensee to Teteven | 812.52 mi (1,307.62 km) |
| Radolfzell am Bodensee to Troyan | 833.51 mi (1,341.41 km) |
| Radolfzell am Bodensee to Tryavna | 868.82 mi (1,398.23 km) |
| Radolfzell am Bodensee to Tutrakan | 883.87 mi (1,422.45 km) |
| Radolfzell am Bodensee to Varna | 966.76 mi (1,555.85 km) |
