All motorists must honk before passing another car, bicyclist, skater, and even a skateboarder.
Lipka, Mitch. Honk Before Passing? Few Do. The Philadelphia Inquirer. 13 Mar. 2003.
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…
Livestock have the right-of-way on public roads.
346.21 Right-of-way of livestock. The operator of a motor vehicle shall yield the right-of-way to livestock being driven over or along any highway but any person in charge of such livestock shall use reasonable care and diligence to open the roadway for vehicular traffic. History: 1993 a. 490.