H16 bulbs share most of the characteristics of Group 1 bulbs given that they belong to this particular class. These lamps are common headlight bulb fittings. But according to UN regulation 37, you are free to use them to address any of your lighting needs. You can utilize them as signal lights, brake lights, parking lights, sidelights, and many more. The regulation, in fact, allows you to use your H16 lamps in projector and reflector headlights as well. With these bulbs, you can enjoy the freedom of choice, as no general regulation governs you.
H16 also use halogen. For that matter, you can expect a few challenges. The life span of these lamps is about 1,000 hours and the quality of the light is not perfect either. But the good news is that you can always upgrade it to LED or HID Xenon to improve your own experience.
These lamps are, however, unique in some ways. They are dual beam bulbs, use PGJ19-3 base, and require 12 volts to generate 19 watts. When you are using W19W, you do not necessarily have to ascertain whether they are road legal. But you need to be sure that this amount of light they produce adequately meets your needs. If not, upgrade.