Dunkirk's Free Buses — Fare-Free Network Launched Together with Frequency Upgrades

Dunkirk's urban community abolished bus fares on 1 September 2018 across a network serving about 200,000 residents. Before the change, fares covered only about 10% of system funding, so the remainder was already public subsidy.
Fare abolition was combined with a network redesign: five express lines every ten minutes and a dozen further lines for lower-density areas. France24 reported weekday ridership up about 60% and weekend ridership more than doubled after the first year; city-commissioned surveys found 48% of new users regularly using the bus instead of driving and about 5% of respondents selling a car or forgoing a second one.
Caveat: the effects cannot be separated from the simultaneous frequency and fleet improvements (the US National Academies' fare-free evaluation framework notes the extension to weekdays accompanied a network redesign), and the survey evidence is self-reported. Ridership figures differ by source (60% to 85% on weekdays).

Read the full analysis: https://www.france24.com/en/20190831-france-dunkirk-free-transportation-bus-success-climate-cities