The proposed tribute would feature an image of a sheep next to the words: “In Memory of the Sheep Who Suffered and Died in a Lorry Accident at This Spot. Try Vegan.”
More than 200 sheep died when the lorry transporting the animals overturned in Dumfries and Galloway on Monday evening. The driver sustained minor injuries.
Police have appealed for witnesses to the crash.
Campaigners claim the memorial would encourage drivers - including those with animals on board - to slow down and travel safely.
PETA director Elisa Allen said: “For nothing more than some chops, this crash left animals suffering on an already terrifying trip, likely to the abattoir.
“PETA’s roadside memorial can prevent further tragedies, including human ones, by reminding people to drive with care and spare a thought for animals by no longer eating them.,