huh. i would never have considered a street direction as part of the street name, any more than I would a house (or block) number. It's all just part of an address, with the direction showing some departure from an arbitrary dividing line on the street.

the exceptions, of course, would be West Avenue (where West may have been some city father) and the like. I might live on, e.g., Aldrich Ave. S. or NE Spring St.; here the placement of the directional modifier at front or back is also quite arbitrary (and coventional).