Motorists in the German city of Leipzig are to be offered free public transport this week in a bid to cut congestion.
The authorities' decision comes amid concerns over commuting times and lengthening traffic jams.
The hope is that motorists will be persuaded to leave their cars at home permanently.
They will have to produce vehicle or driving licences. Families and groups can also travel together on a single document.
Rising fuel prices in Germany have led to recent calls for the tax on petrol to be cut, although commuters are already able to offset their journeys to work against income tax.