The interim settlement was made outside of court on Tuesday as part of an ongoing mediation process, lawyer to the activist Michael Kennedy said.

Legal challenges and protests over the Western Highway duplication project have been ongoing since 2015. Protesters have been camped along the proposed site since June 2018.

"We negotiated through a mediated process and on the eve of going to court on Tuesday - an hour before the hearing - Major Roads said 'look, we've got some positive things to do'," Mr Kennedy said.

"We negotiated for about two hours and then Justice Bromberg (in the Federal Court) then negotiated another two hours over a 3.8 kilometre section of road which our cultural heritage archaeologist identified as least culturally sensitive will be built.

"It is the same result as we would have got three years ago if Major Roads had agreed with the northern alignment."

The stretch of highway runs from Dobie Road to Langi Ghiran Picnic Ground Road and Major Road Projects Victoria confirmed it is not altering its planned duplication project route in order to begin the work.

Mr Kennedy said that Major Road Projects Victoria had agreed it would not bring any machinery or perform any other work, except for surveys conducted on foot, outside of the 3.8 kilometre section of construction between now and a Federal Court hearing scheduled for November.

In that hearing the court will decide whether or not to overturn Federal Environment Minister Sussan Ley's decision not to protect what some Traditional Owners say are culturally significant areas along the proposed highway project.

"If the decision goes our way - and we think it will be reversed, then Major Roads will have no where to go and the opportunity will be there for them to sit down and say 'let bygones be bygones; we may as well build the road in the way you have been wanting it'," Mr Kennedy said.

Substantive works on the rest of the alignment won't begin until a decision is made on the appeal.

A Major Road Projects Victoria spokesman said it was pleasing to be able to start works.

"We're pleased we've been able to reach an agreement that allows for major works to begin on this urgently needed safety upgrade," he said.

"We have all the necessary cultural and heritage permissions for work to commence and expect work to begin in the next few days."

The Ararat Advertiser also asked the following questions of Major Road Projects Victoria:

People camping on the project alignment were notified on August 8 that construction would soon begin and were asked to vacate the site within 14 days.

Read more: