There are many places in the city that will make you sweat bullets as you are driving them,several times we have driven 10-20 blocks under the elevated train tracks marked at 12' 9" not a comfortable feeling.
A driver who lives in the city gave me some good advice once.If the clearance sign is in yellow,you have at least 6" more clearance than the sign says.If the sign is white,that is the true clearance.
And if there is snow accumulation on the road then all bets are off.
At least twice we were scared off of the I-278 and onto Atlantic Ave (not a good road) because of the 12' 9" clearance signs,only to find out later that there is clearance there even for the 13' 6" t/t.DD.