roadsaustralia design proposal
Entry to M31
The southerly alignment links the M9 Motorway to the M31 Hume Motorway roughly 12km south of Campbelltown. This alignment assumes motorists are travelling south, allowing for a more effective bypass of Sydney. However a slightly more northerly alignment from the route could allow the M9 to meet the M31 6km from Campbelltown, which allows for a more effective link to Campbelltown.
The RoadsAustralia proposal chose to use the southerly alignment to enter the M31, prioritising the route as a bypass route, as well as giving more opportunity for development of suburbs further south of Campbelltown; usually new motorways result in more housing around the motorway.
In the south there are two corridor options for the M9 Motorway.
The Easterly Alignment passes very close to the west of Camden before continuing north close to the current-A9. It comes within 4km of the future Western Sydney Airport, continuing east of Mulgoa. Its advantages are that it is closer to both Camden and the future airport, allowing for enhanced connectivity. It is the shorter alignment out of the two options. However its close proximity could be controversial, potentially impeding housing developments and causing noise issues.
The Westerly Alignment passes further west from Camden, before skirting the extreme outer edge of Western Sydney. Passing 7km from the future airport just west of Wallacia, it continues west of Mulgoa. The advantages of this alignment are that it passes further away from city centres, reducing noise levels. However its distance from key centres could impede its overall usefulness and connectivity to the public, thus defeating the purpose of the motorway.
The RoadsAustralia design utilises the easterly alignment, choosing it due to its more enhanced connectivity, primarily to the future Western Sydney Airport.
In the north there are two corridor options for the M9 Motorway.
The Easterly Alignment can connect to both the Easterly and Westerly Southern Alignments. The primary difference between the two alignments is which side of Penrith it passes through. This alignment passes east of Penrith, just west of Erskine Park and St Marys. The route passes through the north of Marsden Park before ending at Windsor Road just south-east of Windsor. It advantages are that it can connect to the larger regions of Western Sydney better, however it may require more land acquisitions than the alternate alignment, most prominently in the currently expanding suburb of Marsden Park.
The Westerly Alignment can also connect to both the Easterly and Westerly Southern Alignments. The alignment passes to the west of Penrith, just west of Jamistown. The route continues north just east of Castlereagh, before terminating at the Bells Of Line Road just west of Richmond. Its advantages are that it requires less land, and will allow for more housing development out further west. However it is slightly longer, and its construction would require the demolition of the Penrith Whitewater Stadium.
The RoadsAustralia design uses the Westerly Alignment, a better link for Western Sydney which can increase connectivity to the furthest parts of Sydney, enhancing transport to Richmond.
Several possible variations in the route exist. The three short ‘links’ are circled in the pictured image, which simply bridge the various alignments together for a seamless route, for example starting on the South-Westerly alignment before bridging onto the South-Easterly in the middle link.