Here in NYC the transit fare is about 35% of the minimum hourly wage for a round trip. I'd guess it's still cheaper than owning and maintaining a car though.

Minimum hourly wage is a terrible metric - very few people make that wage. In your areas where transit is most useful it is also the most economically productive so even less people are making minimum wage than the normal population. I don't the cities in question, but in general these days minimum wages is what you see paid in the economically depressed dying small towns, or people so disabled (generally mentally) that they cannot do your easiest fast food jobs.

How do costs compare for average people in that area is a much better metric. (understand that in transit areas I'd expect people with cars to have newer luxury cars, while in more car centric areas I'd expect more used non-luxury cars, and in poor areas worn out cars - which is itself a skew of the facts)