Two weeks ago, part of Prague's busy Vinohrady neighborhood was turned into an entirely different city. Streets that are usually filled with cars were instead full of stands selling all kinds of ecologically minded products. Visitors to the annual "Experience a Different Prague" ("Zažít město jinak") street festival could also listen to writers giving readings in the streets, watch performances by acrobats and, last but not least, join a round-trip bike ride that took them along routes that are almost never used by cyclists.

Despite the rainy weather, this year's Critical Mass party saw nearly 9,000 visitors and 2,000 bike enthusiasts coming to enjoy the car-free streets and roads of Prague 2. They were supported by ambassadors from cycle-friendly countries such as Denmark, the Netherlands and Austria, and by Czech Transport Minister Vít Bárta, who opened the event and later went for a bike ride himself.

Because of the upcoming local election in mid-October, the street party organizer, the Auto*Mat initiative, arranged a public debate involving the five candidates who are running for mayor in Prague. The main topic of the debate was how to ensure that the growing number of car drivers in Prague aren't keeping people off the streets. "We want to promote city transport, walking and/or pedaling to work," says Auto*Mat's Anna Kotková. "We want the city council to create the conditions for this: to build bike lanes and walking zones."

The Auto*Mat Initiative was established in 2003, thanks to the efforts of artists and activists from the Alfréd ve dvoře theatre group and the ecologically minded civic associations Pražské matky (Prague Mothers) and Oživení (Revitalization). Initially, the activists paid a heavy price for their attempts to promote alternative means of transport in Prague – aggressive drivers swore at them, and the police confiscated their bikes and charged some members with causing an obstruction.

But the Auto*Mat enthusiasts weren't discouraged and gradually found avenues through which they could present their ideas for a "greener" Prague to the public in a less confrontational way. They have initiated negotiations with Prague city council, they organize petitions and they advise on the building of bike lanes.

The city council has never shown much enthusiasm for alternative means of transport but things have begun to improve: 2006 saw the first car-free happening on the Smetanovo nábřeží embankment. On top of that, good quality bike lanes have begun to spread around town, connecting Prague's various outskirts.

Nonetheless, things don't always work out as planned: last year, the council wouldn't allow a Critical Mass ride through the most heavily trafficked part of the city and if it weren't for the support of the Prague 2 district council, no street party would ever take place again.

Much to their credit, Prague 2 authorities have also enforced a "temporary parking rule" for drivers, which, if breached, can lead to their cars being towed away. Prague 2 Mayor Jana Černochová, who was also elected to the national parliament in June, thinks it's a small step in the right direction: "We would like to organize this event [the Critical Mass ride] more often than just once a year. It is clearly very effective: suddenly, we see we can get by without cars in our city. We would all enjoy walking on wide boulevards used by pedestrians, and with a rail route that could be used by old trams."