New York Consolidated Laws, Vehicle and Traffic Law - VAT § 1262. Riding on roadways, shoulders and horse paths

(a) Upon all roadways, horses shall be ridden or led either near the right hand curb or edge of the roadway or upon a usable right-hand shoulder, lane or path in such a manner as to prevent undue interference with the flow of traffic.

(b) Persons riding or leading horses upon a roadway shall do so single file.

(c) Any person riding or leading a horse who is entering the roadway from a private road, driveway, alley or over a curb shall bring the horse to a full stop before entering the roadway.