Luxembourg City may be small, but its traffic congestion is among the worst in the world. A recent study found that Luxembourg drivers spend more time in traffic than those in Los Angeles, a city known for its intense gridlocks and painstaking commutes.

Luxembourg's national government hasn't ignored about the problem. After months of providing no-fare transportation to students and young residents, the country will be the first to offer free public transit to its 110,000 citizens.

Starting in the summer, Luxembourg won't have pay fares on

The ultimate goal is to incentivize people to ditch their cars and start using buses and trains instead. Luxembourg is also working to accommodate a growing share of cross-border commuters.

Luxembourg's train station

Copenhagen aims to build a superhighway for bikes, while Brussels and Hamburg are instituting no-car zones.

But few cities — let alone countries — have managed to extend free public transit to their citizens.

There have been a few notable examples: In 2013, a small city in Estonia offered free transit to curb its population loss, but a follow-up study showed that demand only increased slightly. More than 15 years earlier, the Belgian city of Hasselt offered the same public benefit, before canceling the policy in 2013.

Paris is now testing the idea by giving low-income seniors and disabled residents free monthly passes. Extending this program to all citizens would cost the city around $6.8 billion annually, one study estimated.

Parisians ride their bicycles on the Champs Elysees during a "day without cars."

There's been much debate about whether these policies actually work.

In addition to being expensive for governments, there's a chance that free transit passes won't actually change people's commuting preferences. Multiple experiments have found that no-fare programs merely encourage pedestrians and cyclists to make the switch instead of drivers.

There's also the problem of scaling these programs in big cities like New York and London, which accommodate more than 4 million subway riders a day. With New York's $37 billion worth of subway renovations, it's tough to see where the city would find the money.

In a small country like Luxembourg, the chance of success may be higher, but evidence that it will change long-term driving habits is slim.