| Welling to Mangualde | 838.54 mi (1,349.51 km) |
| Welling to Marco de Canavezes | 810.88 mi (1,304.98 km) |
| Welling to Marinha Grande | 917.97 mi (1,477.33 km) |
| Welling to Massama | 987.94 mi (1,589.93 km) |
| Welling to Matosinhos | 823.78 mi (1,325.74 km) |
| Welling to Mealhada | 867.49 mi (1,396.09 km) |
| Welling to Melgaco | 756.34 mi (1,217.20 km) |
| Welling to Melres | 823.86 mi (1,325.88 km) |
| Welling to Mira | 870.83 mi (1,401.46 km) |
| Welling to Miranda do Corvo | 882.67 mi (1,420.52 km) |
| Welling to Mirandela | 770.65 mi (1,240.24 km) |
| Welling to Mogadouro | 770.75 mi (1,240.41 km) |
| Welling to Moimenta da Beira | 811.71 mi (1,306.32 km) |
| Welling to Moita | 988.32 mi (1,590.55 km) |
| Welling to Moncao | 764.23 mi (1,229.91 km) |
