| Houston to Oliveira de Frades | 4,776.96 mi (7,687.77 km) |
| Houston to Oliveira do Bairro | 4,766.69 mi (7,671.25 km) |
| Houston to Oliveira do Hospital | 4,801.86 mi (7,727.85 km) |
| Houston to Ourem | 4,785.82 mi (7,702.03 km) |
| Houston to Ovar | 4,751.25 mi (7,646.40 km) |
| Houston to Pacos de Ferreira | 4,752.37 mi (7,648.20 km) |
| Houston to Palmela | 4,797.55 mi (7,720.91 km) |
| Houston to Paredes | 4,757.29 mi (7,656.12 km) |
| Houston to Paredes de Coura | 4,728.25 mi (7,609.38 km) |
| Houston to Penacova | 4,783.62 mi (7,698.49 km) |
| Houston to Penafiel | 4,759.52 mi (7,659.71 km) |
| Houston to Peniche | 4,754.00 mi (7,650.82 km) |
| Houston to Peso da Regua | 4,785.07 mi (7,700.82 km) |
| Houston to Pinhal Novo | 4,795.17 mi (7,717.07 km) |
| Houston to Pinhel | 4,829.32 mi (7,772.05 km) |
