| Chicago Heights to Opwijk | 4,146.28 mi (6,672.79 km) |
| Chicago Heights to Ostend | 4,089.78 mi (6,581.87 km) |
| Chicago Heights to Oud-Heverlee | 4,169.11 mi (6,709.53 km) |
| Chicago Heights to Oud-Turnhout | 4,163.97 mi (6,701.27 km) |
| Chicago Heights to Oudenaarde | 4,128.32 mi (6,643.89 km) |
| Chicago Heights to Oudenburg | 4,094.26 mi (6,589.08 km) |
| Chicago Heights to Oupeye | 4,210.16 mi (6,775.59 km) |
| Chicago Heights to Overijse | 4,165.85 mi (6,704.28 km) |
| Chicago Heights to Overpelt | 4,183.61 mi (6,732.88 km) |
| Chicago Heights to Paal | 4,180.81 mi (6,728.36 km) |
| Chicago Heights to Peer | 4,187.96 mi (6,739.87 km) |
| Chicago Heights to Pepinster | 4,221.74 mi (6,794.23 km) |
| Chicago Heights to Peruwelz | 4,139.20 mi (6,661.41 km) |
| Chicago Heights to Perwez | 4,182.06 mi (6,730.37 km) |
| Chicago Heights to Philippeville | 4,187.03 mi (6,738.37 km) |
