| Southborough to Black Forest (Colorado) | 4,738.12 mi (7,625.27 km) |
| Southborough to Blackfoot (Idaho) | 4,771.76 mi (7,679.41 km) |
| Southborough to Blackhawk (California) | 5,365.60 mi (8,635.10 km) |
| Southborough to Blacksburg (Virginia) | 3,903.47 mi (6,282.02 km) |
| Southborough to Blackwells Mills (New Jersey) | 3,519.32 mi (5,663.79 km) |
| Southborough to Blaine (Minnesota) | 4,027.50 mi (6,481.64 km) |
| Southborough to Bloomingdale (Florida) | 4,431.07 mi (7,131.12 km) |
| Southborough to Bloomingdale (Illinois) | 3,988.01 mi (6,418.09 km) |
| Southborough to Bloomington (California) | 5,441.52 mi (8,757.28 km) |
| Southborough to Bloomington (Illinois) | 4,090.67 mi (6,583.30 km) |
| Southborough to Bloomington (Indiana) | 4,057.60 mi (6,530.08 km) |
| Southborough to Bloomington (Minnesota) | 4,047.25 mi (6,513.42 km) |
| Southborough to Bloomsburg (Pennsylvania) | 3,572.31 mi (5,749.08 km) |
| Southborough to Blue Ash (Ohio) | 3,969.14 mi (6,387.71 km) |
| Southborough to Blue Island (Illinois) | 3,985.95 mi (6,414.76 km) |
