If you use your bicycle for transportation, sooner or later you'll find that you have to ride at night or in the rain. Though statistical studies show that it is more dangerous to ride under these conditions, they also show that the overall crash rate for bicyclists who ride regardless of weather is lower than that for bicyclists who ride only on fine days (see Jerrold Kaplan, "Characteristics of the Regular Adult Bicycle User," Federal Highway Administration, 1975). Skill and correct equipment make it easy to ride with confidence.

The no-excuse headlight: A flashlight strapped to the handlebar stem with a bungee cord is legal, and sufficient for city use.

NIGHT RIDING
To ride at night, you need lights. Even when streetlights show you the way, you need lights so other people can see you against the glare of car headlights.
A white headlight identifies the fronts of all vehicles. All states require a bicycle to have a headlight at night. Pennsylvania also requires a rear reflector visible from 500 feet.

TYPES OF BICYCLE LIGHTS
Three major types of lights are available for bicycles: small battery lights, generator systems and the high-powered battery systems. Choose your lights depending on where you ride.
Small battery lights are most useful for riding under streetlights. Aim the headlight so its looks as bright as possible to people ahead of you. Nickel-cadmium rechargeable batteries will cut the cost of operating small battery lights. Most hardware stores sell these batteries and chargers for them.
Unlike small battery lights, a good generator system is bright enough to light your way on dark roads. It's the best choice for long-distance touring, where you may not be able to buy or recharge batteries. Most generator systems go dark when you stop riding; a disadvantage in stop-and-go city riding. Some generator systems have a battery backup that keeps them lighted when you stop.
High-powered battery lights are brightest of all. They're best for night riding under demanding conditions: on dark roads or off-road. They're more expensive and heavier than other bicycle lights, and they need recharging frequently.
When riding at night, carry spare bulbs and batteries for your lights. It's also a good idea to carry a small battery light as a spare to get you home in case your main lighting system goes on the blink.

a) To alert drivers, flash the headlight by twitching the handlebars.

b) Mount a generator or high-powered battery light low, to cast the longest beam.

c) Aim taillights and small battery headlights level. Test aim by rolling the bike toward and away from a wall. The center of the beam should stay at the same height.

USING REFLECTORS
Don't ride at night without a rear reflector and pedal reflectors -- and make sure that your reflectors aren't obscured by baggage or dirt. Reflectors work well for drivers approaching from behind you; they continue to work if your taillight bulb has burned out, or if you're stopped and your generator lights go out.
It's a good idea to use additional reflectors beyond those sold with a new bicycle. Most bicycle shops carry reflective legbands and vests. Adhesive-backed strips of reflective material are also sold for the bicycle frame and fenders. The rear reflector sold on new bicycles isn't as bright as it could be; it has three panels to reflect to the left, right and center. A large automotive reflector is brighter directly behind you where it's really needed. Be sure to aim your rear reflector directly back. If it's tilted up or down, it may not work at all.
Don't consider front and side reflectors to be a substitute for a headlight. Pedestrians stepping off the sidewalk in front of you have no headlights and won't see your reflectors. Motorists pulling out of side streets ahead of you also won't see your reflectors, because these cars' headlights throw their beam straight ahead -- across the road in front of you.
Test your nighttime equipment: Have someone ride your bike past you at night and check to see how well your systems work.

NIGHT-RIDING TACTICS
When riding at night, you can't see drivers inside their cars to make eye contact, but you can flash your headlight at them by twitching the handlebars. Flash your headlight when you need to get the attention of a driver pulling out of a side street.
In some cities, the risk of theft and physical attack in dark, empty places like parks, pedestrian overpasses and industrial areas is generally greater than the risk of crashes on streets with a reasonable amount of traffic, in residential areas and business districts. Choose routes accordingly.
Rural riding at night is the most demanding of your equipment and technique. Most generator lights are not bright enough to allow you to ride downhill at full speed on an unlighted road. Stay within the limitations of your lights.
Two-lane, shoulderless rural roads with moderate to heavy traffic have a bad record for nighttime bicycle crashes. On the other hand, quiet rural roads can be very pleasant to ride at night if your headlight is powerful enough to show you the way.
At night there are generally fewer drivers on the roads; but of these drivers, a much larger percentage are drunk drivers. A useful trick on an unlighted road is to look at your shadow as a car approaches from behind. If the shadow moves to the right, the car is passing to your left.

RIDING IN WET WEATHER
Riding in wet weather can be miserable, but if you equip yourself well, you can stay comfortable.
Many bicyclists carry no wet-weather gear, and they get soaked. Some bicyclists try to use raingear borrowed from the coat rack at home. Long raincoats and ponchos tangle with the spokes or frame. Rubberized rainsuits get as wet inside as out, because they don't let perspiration evaporate.
A bicyclist's rain cape is a fine solution, along with fenders on your bike. The raincape is like a poncho but tailored to fit you in your riding position on the bicycle. It's small and light to carry, and relatively inexpensive to buy. It has loops at the front, which you can hook over your thumbs or the brake levers, extending front like a little tent. A waist strap holds down the back of the cape. The cape should be bright yellow, to make you more visible to drivers.
The rain cape allows ventilation underneath, and so it's the best solution on a warm, rainy day. But with the rain cape, you need a pair of full-length fenders on your bicycle. They keep dirty water and mud from flying up under your cape. A mudflap on the front fender or toeclip covers will keep your feet dry.
High-tech rainsuits of Gore-Tex or other materials that "breathe" can do the job too, especially when equipped with air holes to allow for cooling. Many have reflective stripes to enhance your visibility, too.
Your riding technique needs some modification in wet weather. Rim brakes work poorly if the bicycle has steel rims -- stopping distances may be increased by 10 times. It helps to wipe the rims dry by applying the brakes in advance, well before you need to stop.
There are several ways around the problem of wet-weather braking, among them special leather-faced brake shoes, aluminum rims or a hub brake. One of these is advisable if you ride much in wet weather. Check with your bike shop about the best choice.
In the rain, pay special attention to metal surfaces, such as manhole covers, painted traffic markings, wet leaves and oil slicks. They're all especially slippery. Avoid riding through puddles if you can't see the bottom -- a puddle can hide a pothole.
When you get home, it's a good idea to relubricate your bike chain, to help prevent it from rust.
Equip yourself, use reasonable caution and don't let messy conditions keep you off your bike.