Motorways
Note that the motorway zone boundaries are different from the A-road boundaries shown below.
| Road Number | Location | Trespassed zone(s) |
Reason |
|---|---|---|---|
| M48 | Gloucestershire, Monmouthshire | Zone 5 | This road was formerly the M4, and as it lies both to the north of the current M4 and to the west of the M5, it is in the Motorway Zone 5. |
| M49 | Bristol, Gloucestershire | Zone 3 | This motorway lies entirely within zone 3. The motorway was constructed at the same time as the 2nd Severn Crossing, and it is likely that they used the sequential M48 and M49 for the old M4 and the new motorway respectively. |
| M62 | Merseyside, Greater Manchester | Zone 5 | The section from Liverpool to Manchester was planned as M52, but was added to the M62 to make a cross-country route. |
| M65 | Lancashire | Zone 5 | The short link to the A582 is out of zone |
While the M25 may appear to contradict these rules as it runs through all the London-bound zones, it in fact does not; it does not run in a complete circle, starting in Zone 2, and proceeding clockwise through zones 3, 4 and 1. The A282, which completes the circle mostly formed by the M25, is incorrectly numbered; it proceeds into the A-road 1-zone incorrectly.
The M271 is numbered as a spur of the M27, as opposed to the traditional numbering rules, however the M3 to Southampton came after the M271 was built and is not the zone boundary, which appears to be a straight line from M3 J8 to Exeter in some documentation.
Read more about this topic: Anomalously Numbered Roads In Great Britain