Perhaps the best-known example is the A303, which starts on the A30 near Basingstoke, wends its way across Wessex, then ends on the A30 near Honiton, Devon.
In this list, the "parent road" is shown in brackets. Feel free to add more: just click "edit" above.
Motorways[]
A Roads[]
- A20 (A2, New Cross, to A2, Dover Eastern Docks)
- A282 (M25)
- A303 (A30) surely this starts on the M3?
- A374 (A38)
- A381 (A379)
- A399 (A361)
- A611 (A60, Nottingham, to A60, south of Mansfield)
- A3047 (A30)
- A5093 (A595)
B Roads[]
- B1362 (A1033)
- B3086 (A360)
- B3150 (A35)
- B3205 (A379)
- B3213 (A38)
- B3222 (A396)
- B3253 (A387)
- B3260 (A30)
- B3352 (A38)
- B3413 (A38)
- B4135 (A457, twice, Smethwick)
- B4464 (A454, Willenhall)
- B4578 (A485)
NOTE: The M25 and A282 start and finish on each other!