| South River to Smolyan | 4,841.89 mi (7,792.28 km) |
| South River to Sofia | 4,739.61 mi (7,627.66 km) |
| South River to Sopot | 4,799.81 mi (7,724.54 km) |
| South River to Sozopol | 4,928.86 mi (7,932.23 km) |
| South River to Sredets | 4,911.62 mi (7,904.50 km) |
| South River to Stamboliyski | 4,812.26 mi (7,744.58 km) |
| South River to Stara Zagora | 4,845.43 mi (7,797.97 km) |
| South River to Svilengrad | 4,895.81 mi (7,879.04 km) |
| South River to Svishtov | 4,784.20 mi (7,699.43 km) |
| South River to Targovishte | 4,848.86 mi (7,803.48 km) |
| South River to Teteven | 4,769.15 mi (7,675.20 km) |
| South River to Troyan | 4,788.84 mi (7,706.89 km) |
| South River to Tryavna | 4,821.29 mi (7,759.12 km) |
| South River to Tutrakan | 4,816.68 mi (7,751.69 km) |
| South River to Varna | 4,903.32 mi (7,891.13 km) |
