This guide got started because a caller to the Law Library asked why she couldn't have certain colored headlights on her car. That lead us to look at all sorts of other issues regarding automobile lighti
As is common, federal law in this area sets the minimum standards for motor vehicle safety. States may set higher standards if they wish but they must at least meet the federal standards.
This is one area where you must read statutes and regulations together in order to find the answer to your questions.
New Hampshire statutes and regulations use the words "lamps" and "lights" interchangeably. (Perhaps the word “lamp” harkens back to the days of horseless carriages?) Because of this, the print index to the statutes may be more helpful than keyword searching online. Look under the term “motor vehicles” and then for the subdivision “Lights and Lighting.” Once you get to the appropriate RSA chapter, look at the beginning of the chapter which gives a list of subdivisions and shows you the context of all of the statutes in that section.
If you needed a reason to keep headlights, tail lights, etc. in good working order, the NH Dept. of Safety website linked to below may give it to you. Among other things, the website lists cases in which problems with vehicle lighting were used as justification for a stop.
The administrative rules from the New Hampshire Department of Safety, Saf-C 3215 and 3216, give more detail on the type of lighting equipment each vehicle must have. Fog lamps on school buses (Saf-C 1313.09); how many fog lamps a vehicle may have (Saf-C 3215.05), and more detail about what color emergency lights can be and who can use them (Saf-C 3215.02) are just some of the topics covered in regulations.
Please remember that this guide is for information purposes only and is not comprehensive. It is intended as a starting point for research, to illustrate the various sources of the law, and to provide guidance in their use. NH Law About ... is not a substitute for the services of an attorney.