[TeMPOraL]

Kraków just set up a clean transport zone; it went into full effect just few weeks ago. And people just can't shut up whining about it, even though it doesn't really put much burden on ~anyone. Most people drive petrol-powered cars (usually converted to support LPG, too), and the minimal norms for the clean transport zone are so low, it's hard to find a car that doesn't meet it. You can buy a used petrol-powered car with pocket change and it would already meet the norms.

[inglor_cz]

Kraków badly needs a metro network, just like Prague and Warsaw have. That would alleviate the transport pressure a lot.

[Saline9515]

Those are useful, but not very effective usually as no one controls it after a few months, unless you set up a costly and complex certification and licence-plate monitoring system.