Lights are required for all rides except the 200k. However, if you expect to finish the 200 km in the dark, you must have lights for that brevet as well.

The minimum lighting and reflectors required to meet RUSA's Rules for Riders and the laws of Arizona are:

• A white head light, firmly attached to the bike, visible from at least 500 feet to the front. (A helmit light is not sufficient.)
• A rear steady (not flashing) light, firmly attached to the bike, visible from at least 300 feet to the rear. (A light clipped onto your CamelBak is not sufficient.)
• Reflective ankle bands, visible from the front and rear.
• A reflective vest, sash, Sam Browne belt, or some other device that clearly places reflective material on the front and back of the rider.

Lighting must be used from dusk to dawn and in poor visibility conditions (such as in rain, fog, or sand storm). Each rider, whether riding in a group or by oneself, must fully comply with this requirement. Everyone must use their lights!

What kind of lights?
In my experience, shopping for lights was frustrating. All that talk about watts and lumens was just confusing. It was impossible for me to know how bright the light would be just by looking at it at the bike shop. My suggestion is to give it your best shot. Buy from a bike shop or catalog company that will let you return the light. Try the light at night in a place where there are no street lights. We travel to some very deserted places on our brevets, and the most important thing is to feel comfortable with the lights you've chosen.

Many randonneurs have the dynamo system which generates electricity from a hub in the front axel. These and other systems are discussed on Pam Blayley's web site. Peter White offers several lighting options popular with randonneurs, including hub dynamos. Dynamo systems which do not generate light while at a standstill are acceptable.

Your ability to get by with low-power lighting will depend greatly on riding conditions and chance as well as your own riding speed, skill, night vision, risk tolerance and ability to ride with others. Some riders have been able to complete brevets successfully using only LED lighting, however hitting a road hazard is by far the most common cause of cycling crashes, and can easily result in serious injury or death in spite of protective measures.

Additional reflective material, lighting and backup lighting are both allowed and strongly encouraged. We want you to look like a Christmas tree or UFO at night.

Many riders find helmet-mounted lamps useful for fixing flats, getting the attention of motorists and reading street signs, cue sheets and instrumentation. REI carries a wide variety of headlamps which can be mounted on or adapted to cycling helmets. If you mount a light to your helmet, make sure to use a breakaway mount (such as velcro or small zip ties) so the helmet remains effective in a crash.

Light-colored clothing can aid your visibility in nearly all conditions; a solid white or hi-viz (neon) yellow jersey appears to get the best response from motorists at night. Illuminite clothing also reflects about as much light as light-colored clothing, but the dark colors normally used mean it won't show up as well as light-colored clothing under street lights or during the day. It's a good choice for tights, which are normally black anyway. Illuminite clothing will not meet the requirements for reflective equipment on the rider, since it isn't reflective enough.