The freeway continues through the suburbs of Rockbank and Ravenhall, before eventually terminating at the interchange with Western Ring Road in Derrimut.

This 9.3 kilometre freeway was estimated to cost A$333 million which also includes a grade separated (or "full diamond") interchange at Leakes Road in Rockbank.

Due to the strong population growth of about 8.7 per cent and subdivision in Deer Park and Sunshine, the surrounding suburbs and the seven traffic signals between the Western Ring Road and the start of Western Freeway, substantial long and very frustrating delays were created for the 70,000 vehicles per day with 10 per cent of this consisting of heavy vehicles.

The bypass had been proposed since the completion of the Western Ring Road, the project stalled due to funding quarrels between the Federal and State Governments.

In 2004, the Federal government announced that the Deer Park Bypass would be built as part of a $1.4 billion project "package grant" to Victoria.

On that day, Roads and Ports Minister Tim Pallas and Federal Member for Gorton Brendan O'Connor MP inspected works from the new bridge over the Ring Road at Sunshine West and Tim Pallas announced that the $331 million Deer Park Bypass would open to the public on Sunday 5 April 2009.

[46] The extension of Woolpack Road has been delayed due to controversy over need to clear trees in the heritage listed Avenue of Honour at Bacchus Marsh.

[50] In 2001 work started on a 4.2 kilometre long deviation at Armstrong (on the Adelaide side of Ararat), involving 200,000 cubic metres of earthworks and a new bridge over the main Melbourne–Adelaide railway.

Previously high vehicles could not travel under the rail overpass and were forced to detour around it, in addition the poor road conditions led to a number of accidents and fatalities.

[54][needs update] The clearing of wide swathes of the ancient red gums by VicRoads near Beaufort resulted in expressions of community concern, including public meetings.

In 2015, two women chained themselves to a red gum tree for 4½ hours near Buangor, 74 kilometres (46 miles) west of Ballarat, to draw attention to the issue.