The route forms a key artery on the eastern side of Great Britain and is broadly paralleled by the A1 trunk road. It links London, the South East and East Anglia with Yorkshire, the North East Regions and Scotland. It also carries key commuter flows for the north side of London. It is therefore important to the economic health of a number of areas of the country. It also handles cross-country, commuter and local passenger services, and carries heavy tonnages of freight traffic. The route has ELRs ECM1 - ECM9.