| Union to Opwijk | 4,421.77 mi (7,116.14 km) |
| Union to Ostend | 4,365.18 mi (7,025.09 km) |
| Union to Oud-Heverlee | 4,444.62 mi (7,152.92 km) |
| Union to Oud-Turnhout | 4,439.73 mi (7,145.06 km) |
| Union to Oudenaarde | 4,403.66 mi (7,087.01 km) |
| Union to Oudenburg | 4,369.66 mi (7,032.29 km) |
| Union to Oupeye | 4,485.77 mi (7,219.15 km) |
| Union to Overijse | 4,441.31 mi (7,147.60 km) |
| Union to Overpelt | 4,459.40 mi (7,176.71 km) |
| Union to Paal | 4,456.48 mi (7,172.02 km) |
| Union to Peer | 4,463.72 mi (7,183.66 km) |
| Union to Pepinster | 4,497.32 mi (7,237.74 km) |
| Union to Peruwelz | 4,414.38 mi (7,104.25 km) |
| Union to Perwez | 4,457.50 mi (7,173.65 km) |
| Union to Philippeville | 4,462.22 mi (7,181.25 km) |
