Around 190 Swiss towns are taking part in the European "In Town Without My Car" day, which this year targets commuters.
According to the Swiss Transport and Environment Association, the current high price of petrol is a good reason to consider using other forms of transport.
From Geneva to St Gallen, drivers are being urged to leave their cars at home on Thursday as town centres close to traffic and open up to pedestrians and cyclists. In some cases, towns will be hosting street theatre, live music and dancing events.
The non-governmental Transport and Environment Association used the occasion to issue a reminder that traffic problems are most acute in urban areas. The build-up of traffic is leading to increased congestion and atmospheric pollution in some agglomerations, it warned.
It said the car-free day was the ideal opportunity for drivers to reflect on their use of the car and to consider more environmentally-friendly means of moving around.
The fact that petrol prices had risen and were unlikely to fall in the near future was further food for thought, the association added.
Swiss towns are marking car-free day in different ways. In western Switzerland, apples are being handed out to public transport users in Fribourg and debates have been organised.
In Geneva and Lausanne events will be held to entertain the public with free bike hire in Lausanne.
But unlike in previous years the centre of Geneva will remain open to traffic, although there are traffic exclusions zones being created around schools.
In Bern a march will be held through the old town in the evening, while Biel will put on a special cycle acrobatics show.
Michael Kaufman, deputy director of the Federal Energy Office, has said Switzerland needs to reduce its emissions of harmful greenhouse gases. In ratifying the Kyoto Protocol, the country had pledged to reduce its CO2 emissions from fossil fuels to ten per cent below 1990 levels by 2010.
"In Town Without My Car" takes place every year on September 22.
swissinfo with agencies
In 2004, there were almost 5 million motor vehicles in Switzerland, including 3.8 million private cars.
This means that more than one Swiss in two owns a car.
Every year the average Swiss travels 13,600km.
In 2000, the average Swiss spent 94 minutes a day travelling and covered a distance of 38km.