FIFTY Country Fire Authority volunteers have burnt 20km of grass along the Glenelg highway between Dunkeld and Hamilton.

It is believed to be one of the largest continuous roadside burns in Victoria.

The burn, which is designed to halt any fast-burning grass fires, gives the southern Grampians community a safe exit.

Crews from eight brigades - Warrayure, North Hamilton, Victoria Valley, Karabeal, Tarrington 1 and 2, Grange and Strathkellar - participated this year.

They were unable to do their annual burning last year because of wet weather.

The organisers, Warrayure captain Everard Linke and Tarrington captain Stuart Graham, said the grass-fire danger was high now.

"There is a great deal of grass around this year, two springs' worth, so efforts like this are important," Mr Linke said.

"It gives the community a safer road and also provides great training."

Eighteen brigades were also involved with another 22km burn at Cavendish earlier this month.