VicRoads is alerting drivers near Ararat and Halls Gap that some 70km/h and 90km/h speed limits in the area will change from this week following outcomes of the Victorian Speed Limit Review.

Member for Western Victoria, Simon Ramsay, said in coming weeks, 70km/h and 90km/h signs on sections of Mortlake-Ararat Road and Grampians Road will be changed, making the speed limit less confusing and more consistent.

"Regular users of these roads need to be aware of the change and modify their speed accordingly," Mr Ramsay said.

"These changes will improve safety on our roads as drivers will be less distracted by constant and confusing changes in speed zones.

"All of these speed zone changes have been recommended by experts in road safety and traffic management and follow submissions from over 600 members of the public and stakeholders."

In coming weeks, speed limit signs at the following locations will be replaced. Drivers should be aware of these changes and obey the posted speed limit at all times.

Locations to be reduced from 70km/h to 60km/h include: Mortlake-Ararat Road, between Elizabeth Street and Bryant Road.

Locations where 70kmph will be increased to 80kmph include: Mortlake-Ararat Road, between Bryant Road and Burke Road; Grampians Road, near the Ararat-Halls Gap Road intersection.

"I cannot stress strongly enough that drivers need to be aware of the posted speed limit at all times," Mr Ramsay said.