With fall in full swing and daylight hours shrinking, staying visible on the road as cyclists is more important than ever. While it's always important to wear bright colors and to ride in a predictable manner and place (thereby increasing your visibility by being where drivers expect to see a cyclist), it's also important to go one step further when riding at night by using proper lights and reflectors.
Even the loudest "safety colors" become muted when the full spectrum light of the sun is removed. When riding at times when visibility is reduced, such as at night, in the rain or in fog cyclists should always equip themselves with proper lighting and reflectors. This requirement is not only dictated by the need for safety, it is also a legal requirement in all 50 states.
Here in Illinois the law requires a white front light visible from at least 500 feet and a red rear reflector visible from 100 to 600 feet. A red rear light visible from 500 feet may be used in addition to the reflector. (625 ILCS 5/11‑1507) Bicycle crashes are more likely to occur when visibility is reduced—"I didn't see them" is the number one reason motorists give after a crash for why they collided with a cyclist.
Beyond the legal and safety concerns, not wearing a light at the time of a crash can also severly hinder your case as a bicyclist should you pursue legal action, even if the motorist was in the wrong in every other way.
In addition to using lights and reflectors, consider donning articles of reflective clothing like a safety vest. From a distance, a proper bicycle light will be the first thing a motorist sees. Then as the motorist gets closer to the cyclist, their headlights may overpower the weaker lights of the cyclist, but the headlights will brightly illuminate the reflective tape in most safety clothing. This visibilty can be enhanced even further by attaching reflective tape to your bicycle, specifically at points which are in motion like the wheels or pedals.
Most bicycle lights in the $10-$50 range are designed to make the cyclist more visible to motorists, not to necessarily illuminate the roadway in front of the cyclist. If you find yourself riding at night in areas where streetlights do not adequately illuminate the pavement in front of you, expect to invest more money for a higher power light.
Most drivers are good people who don't want to injure anyone. Give them the every oppportunity to avoid a collision by alerting them to your presence as soon as possible by being a safe, legal cyclist. Be seen, be safe, use the proper lights.
Here's a short Web video from the Chicago Department of Tranportation demonstrating the importance of lights while riding at night.