| Willow Grove to Oerlinghausen | 3,870.95 mi (6,229.69 km) |
| Willow Grove to Oestrich-Winkel | 3,899.73 mi (6,276.02 km) |
| Willow Grove to Offenburg | 3,941.51 mi (6,343.24 km) |
| Willow Grove to Oftersheim | 3,941.68 mi (6,343.53 km) |
| Willow Grove to Ohrdruf | 3,984.66 mi (6,412.69 km) |
| Willow Grove to Ohringen | 3,984.00 mi (6,411.63 km) |
| Willow Grove to Olbernhau | 4,091.47 mi (6,584.58 km) |
| Willow Grove to Olching | 4,088.98 mi (6,580.58 km) |
| Willow Grove to Oldenburg | 3,821.55 mi (6,150.19 km) |
| Willow Grove to Oldenburg in Holstein | 3,890.64 mi (6,261.38 km) |
| Willow Grove to Olfen | 3,827.45 mi (6,159.69 km) |
| Willow Grove to Olpe | 3,864.43 mi (6,219.19 km) |
| Willow Grove to Olsberg | 3,880.91 mi (6,245.71 km) |
| Willow Grove to Oranienburg | 4,023.17 mi (6,474.67 km) |
| Willow Grove to Ortenberg | 3,931.95 mi (6,327.87 km) |
