| Round Rock to Opwijk | 5,081.78 mi (8,178.34 km) |
| Round Rock to Ostend | 5,024.96 mi (8,086.88 km) |
| Round Rock to Oud-Heverlee | 5,104.69 mi (8,215.20 km) |
| Round Rock to Oud-Turnhout | 5,100.58 mi (8,208.60 km) |
| Round Rock to Oudenaarde | 5,063.23 mi (8,148.47 km) |
| Round Rock to Oudenburg | 5,029.41 mi (8,094.05 km) |
| Round Rock to Oupeye | 5,146.14 mi (8,281.92 km) |
| Round Rock to Overijse | 5,101.25 mi (8,209.66 km) |
| Round Rock to Overpelt | 5,120.31 mi (8,240.35 km) |
| Round Rock to Paal | 5,117.07 mi (8,235.12 km) |
| Round Rock to Peer | 5,124.54 mi (8,247.16 km) |
| Round Rock to Pepinster | 5,157.59 mi (8,300.34 km) |
| Round Rock to Peruwelz | 5,073.44 mi (8,164.92 km) |
| Round Rock to Perwez | 5,117.35 mi (8,235.58 km) |
| Round Rock to Philippeville | 5,121.33 mi (8,241.99 km) |
