A 91-year-old woman has chained herself to a large tree east of Ararat, in Victoria's west, to protest against vegetation being cleared for the planned duplication of the Western Highway.

VicRoads estimated about 1,000 trees were being removed between Beaufort and Ararat to make way for the project.

Isabel Mackenzie, who has lived in the area for more than 60 years, said the highway's duplication had led to the loss of native vegetation.

"I am sure there is scope for a road that is less destructive and at the same time has the [same] capacity," she said.

"It doesn't have to be like this."

But VicRoads spokesman Mick McCarthy defended the project, saying the decision was not taken lightly.

"Our approach has been very vigorous for the last three years on this project, in terms of getting planning approval," he said.

"We'll continue working the community as we have with the Ararat Land Care Group as recently as a couple of weeks [ago]. We've been out to see them."

He said VicRoads organised a bus tour of the site for the group.

"We're being very transparent about the process and we'll continue to work with the community," Mr McCarthy said.

The duplication of the highway between Ballarat and Stawell was funded by the state and federal governments.