Scottish councils are being encouraged to create more 20mph zones in residential streets and around schools.
More residential areas could have lower speed limits introduced
Local authorities have been asked to review speed limits, particularly on rural roads, as part of a UK-wide initiative to be implemented by 2011.
However, the AA in Scotland said speed limits may be raised in some places to try and ease congestion.
Last month Aberdeen became the first city centre in Scotland to adopt a blanket "twenty's plenty" speed policy.
The Scottish Executive wants other councils to consider putting similar schemes in place.
However, Neil Greg, head of policy at the AA in Scotland, said despite the focus being on reducing speed limits, the new guidelines will also lead to limits in some areas being raised.
He explained: "There are many locations where the roads have been improved and where the land use has changed on either side of the road.
"So there will be locations where it will be quite safe to increase speed limits."
Chief constable John Vine of the Association of Chief Police Officers in Scotland, said: "Statistics have shown that more motorists are killed on country roads than in towns or cities.
"As a matter of policy, Acpos supports any sound move to make Scotland's roads safer.
"Reducing speed limits in residential areas and on country roads falls within the jurisdiction of local authorities and any decision taken by local government authorities will be acted upon by local police forces."