Since 2008, travellers can pick up a free ticket for public transportation from the machine in the baggage collection area at the Arrival level in the Genève Aéroport. The Unireso ticket, offered by Genève Aéroport, allows you to use public transportation for free in the canton of Geneva for a period of 80 minutes.
If you’re travelling at night, Unireso suggests you use their Noctambus service, a nighttime public transportation network. For more information: www.noctambus.ch.
If you are staying at a hotel, a youth hostel or a campsite, the establishment will offer you the "Geneva Transport Card" that allows you to use public transportation in Geneva free of charge during your stay. Get more information from Genève Tourisme or the establishment concerned.