st marks: whats up with the weird number scheme?

from st marks pl to st marks ave. the numbers don't over lap. but why the two different names. st marks pls goes from 3rd ave ends at 5th ave. and it goes from 1 to 190+. and st marks ave goes from 5 ave and out. it starts from 200+

good question - one for the city planners - avenue usually designates a 2- lane road with trees on both sides, place usually designates a public square or small park. Go figure.