RSA 265:19: When Overtaking on the Right is Permitted.

The driver of a vehicle may overtake and pass on the right of another vehicle only under the following conditions:

I. When the vehicle overtaken is making or about to make a left turn;

II. Upon a roadway with unobstructed pavement of sufficient width for 2 or more lines of vehicles moving lawfully in the direction being traveled by the overtaking vehicle;

III. The driver of a vehicle may overtake and pass another vehicle upon the right only under conditions permitting such movement in safety. Such movement shall not be made by driving off the roadway.