| Silver Spring to Popovo | 5,001.96 mi (8,049.87 km) |
| Silver Spring to Provadia | 5,056.71 mi (8,137.98 km) |
| Silver Spring to Radnevo | 5,034.09 mi (8,101.59 km) |
| Silver Spring to Radomir | 4,901.85 mi (7,888.77 km) |
| Silver Spring to Rakitovo | 4,971.73 mi (8,001.23 km) |
| Silver Spring to Rakovski | 4,995.24 mi (8,039.07 km) |
| Silver Spring to Razgrad | 5,005.51 mi (8,055.60 km) |
| Silver Spring to Razlog | 4,950.38 mi (7,966.86 km) |
| Silver Spring to Ruse | 4,971.01 mi (8,000.07 km) |
| Silver Spring to Samokov | 4,935.46 mi (7,942.85 km) |
| Silver Spring to Sandanski | 4,955.64 mi (7,975.33 km) |
| Silver Spring to Sevlievo | 4,970.58 mi (7,999.37 km) |
| Silver Spring to Shumen | 5,032.62 mi (8,099.23 km) |
| Silver Spring to Silistra | 5,010.17 mi (8,063.08 km) |
| Silver Spring to Sliven | 5,034.06 mi (8,101.53 km) |
