NYC actually reduced local road speeds to 25MPH city-wide like 10 years or so back under Bill de Blasio. It was an uphill fight with state government since the state is who gets to set those speeds unless the locality puts speed signs on every street where there’s an exception, and even NYC didn’t have the money (Or space) to put a speed sign on literally every block in the city. So after decades of 30+ being the norm the city was able to negotiate the state down to 25. 20 would have been better but the state wouldn’t have let it happen and that’s also the pace where New York drivers lose their patience and just start habituating to breaking the rule all the time.