Lisa Johnson finds it easier to grieve at the scene of her son's death
The policy of removing memorials from roadsides in Lincolnshire is in place because of public complaints, highways officials have said.
Mother Lisa Johnson has been told to remove a shrine to her 16-year-old son Jak on the A15 by Friday.
Brian Thompson from the Highways Department said the "difficult decision" to ban the shrines was made after a public consultation.
Mrs Johnson said she found it comforting to visit the road shrine.
Jak died in a road accident in November 2004.
"I can relate more to (that location) - that's how I feel. I go about once or twice a week."
Mr Thompson, from Lincolnshire County Council, said the policy was put in place a few years ago after many people complained about the shrines outside their homes.
Phil Morris who runs Acorn Haulage in Lincoln said it was "insensitive" to order the memorial to be taken down.
He said there was no reason to remove the memorial as it did not pose a hazard and was a good way to remind people of the dangers on roads.
"They do make you think - the knowledge that somebody has died in that location does make you think."
Mrs Johnson put up the 3ft (90cm) high metal cross, which is placed on a grass verge near the road.