Buckingham police are carrying out speed check operations in the town, following some speed limit changes.
The speed limit on Stratford Road has now been reduced to 30mph all the way from the town centre to about 50yds short of the roundabout on the Buckingham bypass. The speed limit on the London Road has also been changed to 30mph all the way into town from the bypass.
Change of speed limit signs have gone up and police will be monitoring traffic speed using mobile equipment.
PC Richard Davis said, for the next couple of weeks, people caught still doing 40mph will be advised of the change of speed limit.
The speed limit on the Buckingham bypass has been reduced to 40mph all the way from the Stratford Road roundabout to the Gawcott/Radclive roundabout.