| Glenn Dale to Popovo | 4,994.21 mi (8,037.40 km) |
| Glenn Dale to Provadia | 5,049.03 mi (8,125.62 km) |
| Glenn Dale to Radnevo | 5,026.19 mi (8,088.87 km) |
| Glenn Dale to Radomir | 4,893.77 mi (7,875.77 km) |
| Glenn Dale to Rakitovo | 4,963.66 mi (7,988.24 km) |
| Glenn Dale to Rakovski | 4,987.27 mi (8,026.24 km) |
| Glenn Dale to Razgrad | 4,997.81 mi (8,043.20 km) |
| Glenn Dale to Razlog | 4,942.25 mi (7,953.78 km) |
| Glenn Dale to Ruse | 4,963.31 mi (7,987.67 km) |
| Glenn Dale to Samokov | 4,927.39 mi (7,929.87 km) |
| Glenn Dale to Sandanski | 4,947.46 mi (7,962.17 km) |
| Glenn Dale to Sevlievo | 4,962.71 mi (7,986.71 km) |
| Glenn Dale to Shumen | 5,024.92 mi (8,086.83 km) |
| Glenn Dale to Silistra | 5,002.59 mi (8,050.89 km) |
| Glenn Dale to Sliven | 5,026.23 mi (8,088.94 km) |
