| Southborough to Portage (Michigan) | 3,880.75 mi (6,245.46 km) |
| Southborough to Portage (Wisconsin) | 3,965.94 mi (6,382.56 km) |
| Southborough to Portales (New Mexico) | 4,948.40 mi (7,963.68 km) |
| Southborough to Porterville (California) | 5,379.04 mi (8,656.72 km) |
| Southborough to Portland (Maine) | 3,209.11 mi (5,164.56 km) |
| Southborough to Portland (Oregon) | 4,940.62 mi (7,951.17 km) |
| Southborough to Portland (Tennessee) | 4,179.72 mi (6,726.62 km) |
| Southborough to Portland (Texas) | 5,048.83 mi (8,125.30 km) |
| Southborough to Portsmouth (New Hampshire) | 3,254.90 mi (5,238.25 km) |
| Southborough to Portsmouth (Ohio) | 3,934.74 mi (6,332.35 km) |
| Southborough to Portsmouth (Virginia) | 3,753.27 mi (6,040.31 km) |
| Southborough to Post Falls (Idaho) | 4,660.66 mi (7,500.61 km) |
| Southborough to Potomac (Maryland) | 3,690.05 mi (5,938.56 km) |
| Southborough to Potomac Park (California) | 5,417.02 mi (8,717.85 km) |
| Southborough to Pottstown (Pennsylvania) | 3,572.01 mi (5,748.59 km) |
