Yellow cabs aren't hard to get in midtown/downtown Manhattan, during rush hour, when you're not going anywhere outside of midtown/downtown. If you tell the taxi driver you want to go to Brooklyn, there's a good chance they'll not take you, regulations forbidding this notwithstanding (how's that for the people who whine that uber isn't "playing by the rules"?) to say nothing if you're starting somewhere like Washington Heights, or out in Queens, or, God forbid, the Bronx.
FWIW I live in Hamilton Heights (aka. lower Washington Heights) and I am bombarded by yellow and green cabs at all hours of the day or night. And it's really easy to hail them because nobody else is interested.
do you live in nyc? rush hour is when it's hard to get a cab in manhattan. and while the effectiveness can vary, calling 311 in the backseat if the driver refuses to deliver was effective in my one experience
