Why is it that in Massachusetts you can turn on red, but in NYC you can't?

Question

Why is it that in Massachusetts you can turn on red, but in NYC you can't?

Answer 1

probably too  much traffic to be safe.

and more people crossing the street running between cars. too easy to miss one and run them over.

Answer 2

Probably because NYC is full of pedestrians that cross the street even though it is red.

Answer 3

I don't know, and it's confusing to have it different in every state. In Canada, everywhere, you can always turn right on a red, after coming to a full stop, unless the signal or sign specifically forbids it at that intersection.