John Macnab's letter ( NCE 16 November) on motorway numbering following the article on the completion the M60 should be an opportunity to debate the numbering system on our motorway network.
Perhaps it is time for a total rethink. Should our motorways have different numbers for each direction of travel or a suffix such as N or S to avoid one of the most common navigation problems - joining in the wrong direction.
Different numbers would be particularly beneficial for circular motorways such as the M25 or M60 and is a procedure long adopted for circular bus services.
The benefit of such numbering would be that directions could be entirely by road number without having to add information such as 'towards Birmingham' or 'westbound' - a process which often involves having to guess from a map how the signs will describe your desired direction.
It would appear to be sensible that the disconnected section of the M62 between Liverpool and Manchester should be renumbered entirely.
As it starts west of the M6 it should logically be an M5x series number as are all other motorways west of the M6.
What about M580 thus returning to the number allocated to the original arterial highway between these cities?
J Kenneth Thomas, Merseyside ken@Thomas.u-net.com