| Harpenden to Dardenne Prairie (Missouri) | 4,196.24 mi (6,753.19 km) |
| Harpenden to Darien (Illinois) | 3,948.71 mi (6,354.84 km) |
| Harpenden to Davenport (Iowa) | 4,056.38 mi (6,528.12 km) |
| Harpenden to Davidson (North Carolina) | 3,962.06 mi (6,376.32 km) |
| Harpenden to Davie (Florida) | 4,403.36 mi (7,086.53 km) |
| Harpenden to Davis (California) | 5,266.40 mi (8,475.46 km) |
| Harpenden to Dayton (Nevada) | 5,161.45 mi (8,306.55 km) |
| Harpenden to Dayton (Ohio) | 3,894.63 mi (6,267.80 km) |
| Harpenden to Daytona Beach (Florida) | 4,280.28 mi (6,888.45 km) |
| Harpenden to De Pere (Wisconsin) | 3,828.06 mi (6,160.66 km) |
| Harpenden to De Witt (New York) | 3,428.84 mi (5,518.19 km) |
| Harpenden to Dearborn (Michigan) | 3,739.96 mi (6,018.88 km) |
| Harpenden to Dearborn Heights (Michigan) | 3,742.26 mi (6,022.59 km) |
| Harpenden to DeBary (Florida) | 4,305.60 mi (6,929.19 km) |
| Harpenden to Decatur (Alabama) | 4,254.92 mi (6,847.64 km) |
