Roadside tributes laid at accident sites could pose a danger to others, according to police and councillors.
Some councils are removing them, worried they could distract other motorists or that people laying flowers could be putting themselves in danger.
Traffic officers from the four Welsh police forces have written to all 22 councils in Wales seeking a solution.
But a friend of four cyclists killed in a road accident said the tributes act as a warning as well as showing grief.
The floral tributes are becoming an increasingly familiar sight on roadsides around the country.
The memorials range from single bunches of flowers to of hundreds of floral tributes, pictures, cards and teddy bears.
Some local authorities have said that the tributes can become a danger to other motorists as well as relatives and friends having to cross busy roads to create the shrines.
In Merthyr Tydfil, the tributes will only be allowed where it is deemed safe and appropriate and they will be removed after three months.
Merthyr Councillor Brendan Toomey said he had seen people putting themselves in danger to reach accident sites, including an adult crossing a main road with a young child to lay a tribute.
He added: "I've witnessed several incidents on the roads of Merthyr Tydfil very recently where people have been crossing the main highway to place tributes.
"They are putting themselves and others in grave danger."
In Bridgend, the council is considering removing some larger tributes where it is feared they could distract motorists.
Councillor Matthew Voisey said he hoped an all-Wales policy could be found for the issue.
He said: "We'd like the police to be involved - we're liaising with South Wales Police.
"However, with the creation of an all-Wales police force, maybe it's the opportunity for either the police or the assembly to look at a national policy that is favourable for everybody to enforce."
South Wales Police road safety officer Nigel Whitehouse said: "We are looking at a policy decision between us all.
"Obviously we have to involve the families in this as well and any ideas that come up from them will be implemented into the policy.
"But we'll work together as a police service and with the Welsh Assembly Government and the local authorities to come up with something hard and fast."
But Roy Spilsbury, a friend of some of the four cyclists killed after a car hit their group near Abergele in January, said that the tributes allow an expression of grief as well as serving as a reminder of the dangers of the roads.
More than two months on from the accident, a tribute remains at the site of the four fatalities.
Mr Spilsbury added: "I think it means something very deep for the families involved.
"It's most important as a reminder to road users in general that these are locations where death can occur."