http://www.euronews.com/2018/05/21/free-public-transport-across-estonia [euronews.com]
Estonia is set to implement free transport for its residents across much of the country as of July 1. The free fare zone will run 24 hours a day, seven days a week.
https://www.citylab.com/transportation/2018/05/estonia-will-roll-out-free-public-transit-nationwide/560648/ [citylab.com]
Estonia is already a world leader in free public transit: In 2013, all public transit in its capital, Tallinn, became free to local residents (but not tourists or other visitors, even those from other parts of the country). The new national free-ride scheme with extend this model even further, making all state-run bus travel in rural municipalities free and extending cost-free transit out from the capital into other regions.