| Rockville to Dover (New Hampshire) | 432.14 mi (695.46 km) |
| Rockville to Dover (New Jersey) | 185.44 mi (298.43 km) |
| Rockville to Dover (Ohio) | 250.37 mi (402.92 km) |
| Rockville to Downers Grove (Illinois) | 600.63 mi (966.61 km) |
| Rockville to Downey (California) | 2,283.62 mi (3,675.13 km) |
| Rockville to Dranesville (Virginia) | 12.99 mi (20.91 km) |
| Rockville to Draper (Utah) | 1,833.23 mi (2,950.30 km) |
| Rockville to Drexel Heights (Arizona) | 1,950.95 mi (3,139.76 km) |
| Rockville to Drexel Hill (Pennsylvania) | 115.41 mi (185.73 km) |
| Rockville to Duarte (California) | 2,268.46 mi (3,650.73 km) |
| Rockville to Dublin (California) | 2,399.75 mi (3,862.02 km) |
| Rockville to Dublin (Georgia) | 555.83 mi (894.53 km) |
| Rockville to Dublin (Ohio) | 326.65 mi (525.69 km) |
| Rockville to Dubuque (Iowa) | 746.17 mi (1,200.84 km) |
| Rockville to Duluth (Georgia) | 522.97 mi (841.64 km) |
