Numerous calls have been made to extend the motorway to link Manchester and Sheffield, the second and ninth most populous urban areas within the United Kingdom. Traffic between the cities is mainly divided between the Snake and Woodhead passes, which traverse the Peak District. Plans for a £180m improvement to the route by bypassing Mottram and Tintwistle, the A57/A628 Mottram in Longdendale, Hollingworth and Tintwistle Bypass, and the 'Glossop spur' linking to the A57 road are currently at the public inquiry stage but were 'suspended indefinitely' in January 2008. There are now proposals to link the two cities with a tunneled scheme underneath the Peak District, some of the proposed routes using the existing M67 route.