A | 5 miles (8 km) or less, including downtown termini |
B | 5 to 10 miles (8 to 16 km) |
C | 10 to 15 miles (16 to 24 km) |
D/3 | 15 to 20 miles (24 to 32 km) [note 3] |
E | 20 to 25 miles (32 to 40 km) |
F | 25 to 30 miles (40 to 48 km) |
G | 30 to 35 miles (48 to 56 km) |
H | 35 to 40 miles (56 to 64 km) |
I | 40 to 45 miles (64 to 72 km) |
J | 45 miles (72 km) or more |