A new Road Numbering System The NSW Government has made significant improvement to how motorists can find their way across NSW. Transport for NSW has implemented a new system of alpha-numeric route numbering. This dataset provides you with the important changes to NSW, and additional information regarding the program. Route numbers and road names The existing 'shield' route markers have been replaced with a combination of a letter - either an M (motorway), A (route of national significance) or B (route of state significance) - and a number from 1 to 99. NSW Route Number Map