Chicago for example has both. Phoenix, las vegas. As do a number of medium-large cities in the southeast like raleigh, tampa, charleston SC. Maybe not cities that come to mind first when talking about urban centers but they are million+ population agglomerations with plentiful parking and serious pedestrian death problems. Tens of millions of americans live in these "small" cities of around a million, so trends across them end up affecting a huge population.
Another factor is that urban speed limits vary widely in how much they are actually limits. Research is clear on the fact that road design has at least as strong an influence on driver behavior as posted limits do. Without rigorous enforcement & given the wide streets common in these places, driver behavior tends towards interpreting the limit as the minimum speed they are entitled to, rather than the maximum to be attained only when safe.
And finally neither I nor anyone else here know what you've seen so that's a very silly limit to place on the conversation.
Another factor is that urban speed limits vary widely in how much they are actually limits. Research is clear on the fact that road design has at least as strong an influence on driver behavior as posted limits do. Without rigorous enforcement & given the wide streets common in these places, driver behavior tends towards interpreting the limit as the minimum speed they are entitled to, rather than the maximum to be attained only when safe.
And finally neither I nor anyone else here know what you've seen so that's a very silly limit to place on the conversation.