„…the city whose population does not exceed…“
„…the city the population of which does not exceed…“

Ktera veta je spravne? Vypada ze obe, ale nekde tady na HFE jsem narazil na nejakou vetu kde byla spravne ta druha varianta(jiny kontext) a od te doby to u nezivotnych veci pouzivam s ‚of which‘, a ‚whose‘ jsem myslel ze je spatne a pry neni 

Obě varianty jsou správně. V dnešní době se používá většinou první varianta s whose – jak pro životná tak i neživotná podst.jména.
Spojení of which už není tak frekventované a platí pouze pro neživotné předměty.

Ja si nepamatuju jestli v tom testu na HFE byla moznost whose, ale vim ze spravne bylo of which…proto me to zmatlo. diky:)

ano, správně jsou obě. V testu to určitě takto nebylo.

I think in the second example, there should be a comma after „the city“ and then again after „the population of which.....“ (subordinate clause)

i.e.

The city, the population of which does not exceed 200,000 people, is still able to support an effective public transportation system.

Something like that. Otherwise it sounds strange without the comma and should be rewritten.

it depends on whether it's a restrictive relative clause or not. You use a comma if it's just an extra piece of info. If, however, THE CITY is defined by the subordinate clause, you don't use a comma.

Although we're a bit in the dark about the context here, it's quite clear that it IS a defining clause, so there should NOT be commas. In your sentence – it's a different case, COMMAS HAVE TO BE THERE.

I agree with you in the case of the first sentence – „That city over there, that city whose population does not exceed…“ but as an NS, the second formulation sounds (and looks) very odd to me without commas…I have a friend who is an English teacher in the US – I'll ask him just to be sure