New York Consolidated Laws, Vehicle and Traffic Law - VAT § 1128. Driving on roadways laned for traffic

(a) A vehicle shall be driven as nearly as practicable entirely within a single lane and shall not be moved from such lane until the driver has first ascertained that such movement can be made with safety.

(b) Upon a roadway which is divided into three lanes and provides for two-way movement of traffic a vehicle shall not be driven in the center lane except when overtaking and passing another vehicle traveling in the same direction when such center lane is clear of traffic within a safe distance, or in preparation for making a left turn or where such center lane is at the time allocated exclusively to traffic moving in the same direction that the vehicle is proceeding and such allocation is designated by official traffic-control devices.

(c) When official traffic-control devices direct slow-moving traffic, trucks, buses or specified types of vehicles to use a designated lane or designate those lanes to be used by traffic moving in a particular direction regardless of the center of the roadway, drivers of vehicles shall obey the directions of every such sign, signal or marking.

(d) When official markings are in place indicating those portions of any roadway where crossing such markings would be especially hazardous, no driver of a vehicle proceeding along such highway shall at any time drive across such markings.