| Duncan to Popovo | 6,008.79 mi (9,670.21 km) |
| Duncan to Provadia | 6,058.17 mi (9,749.68 km) |
| Duncan to Radnevo | 6,051.34 mi (9,738.70 km) |
| Duncan to Radomir | 5,932.93 mi (9,548.13 km) |
| Duncan to Rakitovo | 6,001.53 mi (9,658.54 km) |
| Duncan to Rakovski | 6,017.86 mi (9,684.82 km) |
| Duncan to Razgrad | 6,009.21 mi (9,670.89 km) |
| Duncan to Razlog | 5,984.21 mi (9,630.65 km) |
| Duncan to Ruse | 5,975.38 mi (9,616.44 km) |
| Duncan to Samokov | 5,965.15 mi (9,599.97 km) |
| Duncan to Sandanski | 5,992.95 mi (9,644.71 km) |
| Duncan to Sevlievo | 5,986.30 mi (9,634.02 km) |
| Duncan to Shumen | 6,036.09 mi (9,714.14 km) |
| Duncan to Silistra | 6,004.64 mi (9,663.54 km) |
| Duncan to Sliven | 6,045.92 mi (9,729.97 km) |
