A typical traffic jam in la grande rue, Preuilly-sur-Claise.
The local council has recently introduced restrictions to parking in the main street of Preuilly in an attempt to reduce the traffic congestion. This street is now Zone bleue parking, which means you are limited to 2 hours and must have a blue parking disk on the dashboard. The way it works is that you set the parking disk to show the time you arrived, so that the parking inspector can check you have not overstayed. It is a system that relies on having a parking inspector in the first place (I'm not sure who's designated in that role in Preuilly) and they have to do the rounds of the Zones bleues regularly, to pick up overstayers and liars.
Zones bleues are in force all over France, and you can identify a parking spot as in such a zone by the fact that it is delineated in blue paint. So far I haven't seen a single person in Preuilly displaying a parking disk on the dash, and it doesn't seem to have substantially reduced the number of cars parked in the main street. Why would it? It's always mostly been a steady stream of people parked for half an hour to an hour while they do their business in town. There is parking in the market place (except when the market is on), in front of the Post Office, next to the abbey and in front of the Hôtel de Ville (town hall) -- all small areas of around a dozen places or less, and usually about three quarters full. All involve a walk of less than 50 m to the main street.
If the council really want to solve the traffic congestion problem, they need to bite the bullet and ban parking in la grande rue altogether except for deliveries and arrêts minutes. Unfortunately, the businesses along the street are convinced their trade would suffer and are against a ban. This is despite having the occasional vehicle reverse into plate glass windows and the vibration of the heavy goods carriers break others as they rumble their stop-start way through town. One good thing though is that because of the crowded main street and the zigzag layout of the route through town, Preuilly hasn't had to create a chicane like many of the surrounding villages now have to slow cars down.