Cornwall Council is marking Clean Air Day with events to help reduce engine idling. They are visiting St Austell, Camelford and Launceston.
Volunteers from the town councils will be giving advice to drivers waiting in traffic queues about the benefits of switching off their car engines.
Clean Air Day is about tackling and raising awareness of air pollution.
The council says there are nine Air Quality Management Areas (AQMAs) in Cornwall where traffic related air pollution is higher than the government's recommended level.
An AQMA is an area that has higher levels on nitrogen dioxide gas than they should; vehicles being the main source of the gas.