Drivers must warn those who they pass on highways before they do so.

39:4-85. Passing to left when overtaking; passing when in lines; signalling to pass; passing upon right

The driver of a vehicle overtaking another vehicle proceeding in the same direction shall pass at a safe distance to the left thereof and shall not again drive to the right side of the roadway until safely clear of the overtaken vehicle. If vehicles on the roadway are moving in two or more substantially continuous lines, the provisions of this paragraph and section 39:4-87 of this Title shall not be considered as prohibiting the vehicles in one line overtaking and passing the vehicles in another line either upon the right or left, nor shall those provisions be construed to prohibit drivers overtaking and passing upon the right another vehicle which is making or about to make a left turn.

The driver of an overtaking motor vehicle not within a business or residence district shall give audible warning with his horn or other warning device before passing or attempting to pass a vehicle proceeding in the same direction.

The driver of a vehicle may overtake and pass another vehicle upon the right as provided in this section only under conditions permitting such movement in safety. In no event shall such movement be made by driving off the pavement or main-traveled portion of the roadway.

Amended by L.1951, c. 23, p. 82, s. 45.