| Castanet-Tolosan to Opwijk | 529.91 mi (852.81 km) |
| Castanet-Tolosan to Ostend | 536.83 mi (863.94 km) |
| Castanet-Tolosan to Oud-Heverlee | 526.92 mi (848.00 km) |
| Castanet-Tolosan to Oud-Turnhout | 562.93 mi (905.94 km) |
| Castanet-Tolosan to Oudenaarde | 516.22 mi (830.78 km) |
| Castanet-Tolosan to Oudenburg | 534.40 mi (860.03 km) |
| Castanet-Tolosan to Oupeye | 533.60 mi (858.75 km) |
| Castanet-Tolosan to Overijse | 521.89 mi (839.90 km) |
| Castanet-Tolosan to Overpelt | 562.60 mi (905.41 km) |
| Castanet-Tolosan to Paal | 547.45 mi (881.03 km) |
| Castanet-Tolosan to Peer | 557.74 mi (897.59 km) |
| Castanet-Tolosan to Pepinster | 527.69 mi (849.23 km) |
| Castanet-Tolosan to Peruwelz | 493.55 mi (794.29 km) |
| Castanet-Tolosan to Perwez | 515.22 mi (829.16 km) |
| Castanet-Tolosan to Philippeville | 483.72 mi (778.48 km) |
