It is a car sharing service where members can reserve a vehicle up to 30 days in advance, for a maximum of 30 days. This service is very similar to renting a vehicle from a car rental agency, except that the vehicles are self-service (24/7). Cars can be accessed at various Communauto stations throughout the metropolitan area. The vehicle you reserve with this service must be brought back to the same station where you originally picked it up.
In Chrono, you will find Communauto in the “Mobility” tab under the map. This service is also available from the app’s menu.