| Western Springs to Oerlinghausen | 4,270.23 mi (6,872.28 km) |
| Western Springs to Oestrich-Winkel | 4,320.08 mi (6,952.50 km) |
| Western Springs to Offenburg | 4,376.22 mi (7,042.85 km) |
| Western Springs to Oftersheim | 4,365.92 mi (7,026.27 km) |
| Western Springs to Ohrdruf | 4,387.97 mi (7,061.76 km) |
| Western Springs to Ohringen | 4,406.66 mi (7,091.83 km) |
| Western Springs to Olbernhau | 4,487.13 mi (7,221.33 km) |
| Western Springs to Olching | 4,514.18 mi (7,264.87 km) |
| Western Springs to Oldenburg | 4,210.57 mi (6,776.26 km) |
| Western Springs to Oldenburg in Holstein | 4,259.51 mi (6,855.02 km) |
| Western Springs to Olfen | 4,233.31 mi (6,812.85 km) |
| Western Springs to Olpe | 4,275.65 mi (6,880.99 km) |
| Western Springs to Olsberg | 4,286.79 mi (6,898.92 km) |
| Western Springs to Oranienburg | 4,399.50 mi (7,080.31 km) |
| Western Springs to Ortenberg | 4,345.42 mi (6,993.28 km) |
