This article covers numbered east-west streets in Manhattan, New York City. Major streets have their own linked articles; minor streets are discussed here. The streets do not run exactly east–west, because the grid plan is aligned with the Hudson River rather than with the cardinal directions. "West" is approximately 29 degrees north of true west. 

The numbered streets carry crosstown traffic. In general, even-numbered streets are one-way eastbound and odd-numbered streets are one-way west. Several exceptions reverse this. Most wider streets carry two-way traffic, as do a few of the narrow ones. 

Streets' names change from West to East (for instance, East 10th Street to West 10th Street) at Broadway below 8th Street, and at Fifth Avenue from 8th Street and above. 

Although the numbered streets begin just north of East Houston Street in the East Village, they generally do not extend west into Greenwich Village, which already had streets when the grid plan was laid out by the Commissioners' Plan of 1811. Streets that do continue farther west change direction before reaching the Hudson River. The grid covers the length of the island from 14th Street north.
in manhattan, what are the streets aligned to?
where do streets change from East to West?
how far off of true north is "west"
which direction do odd numbered streets go?
and even numbers?
what carries traffic across town?
do they extend into Greewich village?
what does the grid cover?
from what point?
why aren't Greewich streets numbered?
since when?
what dictated that?
the Hudson River
the Hudson River 
at Broadway below 8th Street
 at Broadway below 8th Street
29 degrees north
29 degrees north
one-way west
one-way west
one-way eastbound
 one-way eastbound
The numbered streets do
The numbered streets
NO
do not extend west into Greenwich Village
the length of the island
 the length of the island
14th Street north
14th Street north
They already had streets when the grid plan was laid out
already had streets when the grid plan was laid out 
1811
1811
the Commissioners' Plan
the Commissioners' Plan