If you’re on the road at dawn or dusk for your commute, it’s extremely important that you make yourself visible. This is more than just a legal requirement, it’s a matter of personal safety. The reflectors that most people immediately remove from their new bikes (if they even came with them) provide visibility from the front, side, and rear of your bike. They provide the very minimum of visibility. Consider supplementing them with inexpensive LED lights – white in front and red out back, for an added measure of safety. Most rear lights have one or more flashing settings, which are generally more visible. They run on flat watch-style batteries, or inexpensive AA and AAA batteries, and generally last quite some time. Rechargeable, even USB rechargeable lights, are available too. Combine that with an reflective ankle strap if you happen to be wearing long pants, and you greatly increase your chances of not becoming a traffic statistic.
For commutes that take place well before sunrise, or after sunset, consider a headlight that illuminates the road, rather than just making you visible to motorists. This can help you avoid running over glass, nails, small children, wild animals, and other debris. Prices range from less than $20 for simple models running on replaceable batteries, to ones that cost hundreds of dollars and will literally “light up the night” and offer long run times from their rechargeable battery packs. Keep in mind that you frequently get what you pay for, and a bright light with substantial battery life won’t come cheap.
Some lighting resources:
Modern Bike is a brick and mortar store with an online shop that carries an extensive array of brands
JensonUSA has lights priced from $5 LED units to $600+ for 1400 lumen monsters
Bikesomewhere offers free shipping on orders over $75