| Hartford to Opwijk | 3,550.09 mi (5,713.32 km) |
| Hartford to Ostend | 3,492.49 mi (5,620.61 km) |
| Hartford to Oud-Heverlee | 3,573.07 mi (5,750.31 km) |
| Hartford to Oud-Turnhout | 3,573.36 mi (5,750.76 km) |
| Hartford to Oudenaarde | 3,529.40 mi (5,680.02 km) |
| Hartford to Oudenburg | 3,496.79 mi (5,627.54 km) |
| Hartford to Oupeye | 3,615.82 mi (5,819.10 km) |
| Hartford to Overijse | 3,568.97 mi (5,743.70 km) |
| Hartford to Overpelt | 3,593.32 mi (5,782.89 km) |
| Hartford to Paal | 3,588.15 mi (5,774.57 km) |
| Hartford to Peer | 3,596.99 mi (5,788.79 km) |
| Hartford to Pepinster | 3,626.62 mi (5,836.48 km) |
| Hartford to Peruwelz | 3,537.15 mi (5,692.50 km) |
| Hartford to Perwez | 3,584.53 mi (5,768.74 km) |
| Hartford to Philippeville | 3,584.86 mi (5,769.27 km) |
