| Prospect Heights to Opwijk | 4,129.08 mi (6,645.11 km) |
| Prospect Heights to Ostend | 4,072.73 mi (6,554.42 km) |
| Prospect Heights to Oud-Heverlee | 4,151.88 mi (6,681.80 km) |
| Prospect Heights to Oud-Turnhout | 4,146.32 mi (6,672.86 km) |
| Prospect Heights to Oudenaarde | 4,111.36 mi (6,616.59 km) |
| Prospect Heights to Oudenburg | 4,077.22 mi (6,561.64 km) |
| Prospect Heights to Oupeye | 4,192.75 mi (6,747.58 km) |
| Prospect Heights to Overijse | 4,148.68 mi (6,676.66 km) |
| Prospect Heights to Overpelt | 4,165.92 mi (6,704.40 km) |
| Prospect Heights to Paal | 4,163.30 mi (6,700.18 km) |
| Prospect Heights to Peer | 4,170.31 mi (6,711.47 km) |
| Prospect Heights to Pepinster | 4,204.38 mi (6,766.30 km) |
| Prospect Heights to Peruwelz | 4,122.48 mi (6,634.49 km) |
| Prospect Heights to Perwez | 4,164.93 mi (6,702.81 km) |
| Prospect Heights to Philippeville | 4,170.27 mi (6,711.39 km) |
