The additional funding will be used to duplicate a further 15.5 kilometres of the Western Highway between Beaufort and Buangor and build a bypass of Buangor.

Northern Grampians Shire Mayor, Cr Kevin Erwin who is also the chair of the Western Highway Action Committee, said announcements of additional funding are always gratefully received.

Lobbying will step up a gear in a fortnight's time with the duplication through to Stawell a high priority when Cr Erwin meets with Federal Transport Minister Warren Truss in Canberra.

The additional funding brings the Australian Government contribution to $404 million, with the Victorian Government providing $101 million to the $505 million project.

"By reducing transit times and improving safety, we are boosting productivity and delivering on our promise to duplicate the Western Highway from Ballarat to Buangor," Assistant Minister for Infrastructure and Regional Development Jamie Briggs said.

"The Australian Government recognises that reliable and effective transport infrastructure throughout Victoria is essential to the prosperity of both the state and national economies.

"This is another example of the Infrastructure Prime Minister's commitment to building a stronger and more prosperous Australia through well targeted infrastructure investment.

"The new funding will ensure the duplication of Section 2a can commence later this year."

Thirty-five percent of the traffic on the Western Highway between Ararat and Stawell is heavy vehicles.

Ararat Rural City Mayor, Cr Paul Hooper has also welcomed confirmation of the additional funding.

"The quicker we get to duplicating the Western Highway, right the way through the better it will be for everybody, now we focus for Buangor onwards.

"The sooner it is completed the safer it will be, improve amenity, cut travel times and enable easier access to education and health services across the region."

Federal Member for Wannon Dan Tehan said the works would provide a four lane dual carriageway and a bypass north of Buangor.

"This important upgrade will improve road alignment standards and eliminate the need for vehicles to queue behind slow or turning vehicles," Mr Tehan said.

Victorian Minister for Roads Terry Mulder said that work continues to progress well on sections already under construction.

"Later this month, motorists will be moved onto a newly constructed 14 kilometre section between Burrumbeet and Trawalla," Mr Mulder said.

"This is the longest section to be opened since construction began in 2010, so it is a significant milestone for us."

The duplication of the Western Highway from Ballarat to Buangor is expected to be completed in late 2015.