 I've been driving for more than 40 years and it's never been a problem for me driving at night. Well, at least until a few years ago. Now, I seem to be having a harder time seeing things on the road after it gets dark. I can't understand it. Man, I just got my license. It's great. Me and my buddies all have cars. Sometimes on a Friday night, you can see it's just cruising the town. Well, maybe we go to our friend's house to just see what's up. I have a full-time job that's very demanding and two-year-old twins who are even more demanding so you can imagine I keep real busy. In fact, I probably have the dirtiest car on the road since I never have the time to wash it. I mean, I'm putting the kids in the van to take them to daycare even before the sun comes up. I could really use a rest. I usually get home late from work. I need to work off some stress. You know, get some exercise. So I try to go jogging, even if it is dark. I try and stay as close to the edge of the road as I can so I don't get hit by a car. Just about all of us have a driver's license, and every day we depend on our cars to get us where we need to go, whether to work, to a friend's house, to the shopping mall, or to a vacation spot in another state. But since driving is an everyday activity, we can sometimes take that privilege for granted. And unfortunately, we can also take safety for granted. However, if we do that, even for a moment, the unexpected can happen. A vital traffic control device along the roadway might be overlooked, which is something that could more easily happen while driving at night. So what's being done to help improve the potential visibility of traffic control devices at night? Well, quite a bit, but a lot still depends on drivers like you and me. As far as roadway safety is concerned, it's essential that we're alert, that we keep our vehicles in good working order, and that we appreciate the differences between driving at night and driving during the day. Through experience, most of us know that it's more difficult to see the road at night. But what's being done to help improve our ability to see traffic control devices during those hours? Well, it has to do with something that's called retro-reflectivity. Simply put, retro-reflectivity is a phenomenon in which light rays strike a surface and are then reflected back towards the direction of the light source. To a driver, this makes traffic safety devices appear to illuminate or glow. Federal, state, and local government agencies, working together with academia and the traffic safety services industry, are dedicated to developing and maintaining a safe, efficient roadway system for both daytime and nighttime driving. That's where retro-reflective technology comes in. It increases the effectiveness of a car's headlights, making road signs, pavement markings, and roadway safety devices more visible at night. So, what makes retro-reflectivity possible? Well, there are two basic technologies involved. The first type uses small glass beads. These tiny round spheres aren't much larger than a grain of salt. They're applied to materials that are used in manufacturing traffic safety devices, like white and yellow paints, thermoplastics, and epoxies, making them retro-reflective. These same beads are used in making retro-reflective sheeting that's applied to signs and roadway safety devices, as well as other items like safety vests. In essence, each glass bead works like a small directional mirror. Together with the material that's behind it, a bead turns incoming light around, reflecting it back to its source. The second basic technology that the traffic safety services industry uses is prismatic reflectors. These prismatic retro-reflective materials work somewhat differently from glass beads, as they redirect the light back to the source through multiple internal reflectors. Familiar types of roadway safety devices using prismatics include reflectors that are positioned on roadside markers and barriers, as well as the raised retro-reflective pavement markers that are increasingly being used on otherwise dark roadways. Prismatic retro-reflective materials consist of tiny cube-corner retro-reflective elements. Positioned on the face of signs and road channelizing devices, each element is a tiny corner cube that's open in the direction of the driver. When a headlight beam enters the cube, it bounces off each mirrored face of the cube-corner element, ultimately reflecting light back towards the driver's eyes. It makes roadway safety devices look as if they're glowing. But no matter how efficient this technology is, it can't be effective without something else, something that's extremely important, you, the driver. It seems like before I turned 60, I could spot things a lot easier at night. But now, whenever I'm driving after dark, it seems like I really have to work at it. I just know I need to get a lot closer to signs to see them. Years ago, I could see them pretty far away. As we grow older, our eyes increasingly need more light to see. By the age of 45, the average person needs four times as much light to see at night as a person at age 19. That's one of the reasons why the use of retro-reflective materials on roadway safety devices is so very important. Retro-reflectivity gives America's maturing population a better opportunity to drive safely at night. It does that by allowing them to see roadway signs, markings, and safety devices a lot sooner, and a lot better. But retro-reflectivity can only be effective if all drivers are as alert as possible. This means being careful with medications and getting adequate rest, in addition to making sure that their car's headlights are clean and properly aligned. Drivers, no matter what age, also need to realize that adverse weather can seriously affect their ability to drive safely at night. For example, if there's heavy fog, rain, or snow, the beams from a car's headlights can become scattered and produce glare, which limits vision. But this concern involves more than just diminished visibility. Consider that even light rain can reduce the retro-reflective properties of signs, markings, and roadway safety devices. Here's why. When rain, fog, or snow, the transmission of light to and from a retro-reflective device is greatly reduced or even totally eliminated. So during adverse weather, it's important to stay off the roads if possible. But in case doing that isn't practical, then you need to drive more slowly and cautiously. Also, make sure that your windshield wipers, lights, and defroster work properly. On Saturday nights when I go driving out with my friends, we have a great time. I mean, we're not getting in trouble or anything. We're just messing around. In a car, innocent horseplay can cause the driver to look away from the road at exactly the wrong time, missing something important, like a stop sign, even if it's clearly visible and made of retro-reflective material. Traveling too fast in relation to driving conditions can also have very severe consequences. That's because at night, or in adverse weather, a driver is almost totally dependent on the visibility that's provided by a car's headlights. Roadway lighting is a highly effective method for increasing nighttime visibility and for preventing accidents. But unfortunately, it's not practical to have it in place everywhere. That's why when driving on a dark road using only your headlights, it's important to concentrate on what you're doing. This demands that you use your car's high beams whenever possible, helping you to more easily see retro-reflective signs, markings, and roadway safety devices from a distance. I've got my two little kids in the car, so I'm a very careful driver. I wouldn't want anything to happen to them, or to me for that matter. So if it's raining really hard or something, I take it easy. Thinking about that, a good rainstorm would help clean off my dirty van. When it comes to driving on dark roads, a dirty vehicle isn't anything to joke about, and here's why. The dirt that accumulates on a car isn't just unsightly. It can actually cause an accident. No joke. The build-up of grime on your headlights allows less light to reach signs along the road, meaning that less light gets reflected back to you. While we're on the subject, in addition to keeping your car clean, it's essential that things like headlights, tail lights, and windshield wipers be in good working order. This means both headlights need to be functioning. If one burns out, it needs to be replaced as quickly as possible. And the same goes for your tail lights. Another point is that headlights must be properly aligned. In this way, their beams are focused exactly as they should be. Also, you should replace your car's windshield wipers periodically. That's so they don't wear down to the point of smearing your windshield instead of wiping it clean. When I go jogging at night, I try to wear light-colored clothing. That way I can be seen a lot easier. But I have to admit, there have been a few close calls. Jogging, riding a bike, or just taking a walk along a road, even one that's not heavily traveled by cars, should be done only during daylight hours. But if it's after dusk, it's important to wear more than just lightly-colored clothing. To be easily seen at night, a retro-reflective vest should be worn, like those used by crews in construction work zones along the highway. It's also advisable to wear a small, battery-operated flashing light. Both of these safety items are available through retail sporting goods stores. If you're riding a bike on a dark road, be sure it has a state-approved bicycle headlight. And in addition to the retro-reflective vest you should be wearing, your bike needs to have retro-reflective devices on its pedals, seat, and wheels. Only by taking these kinds of precautions will other drivers be able to see you from farther away, giving them more time to maneuver around you. Driving at night presents a number of hazards. But these can be reduced through a combined effort between federal, state, and local governments and the traffic safety services industry, in addition to drivers, bicyclists, and pedestrians. On the part of government, this involves having effective maintenance programs in place, ones that are designed to systematically refurbish road signs, pavement markings, and roadway safety devices after they've reached the end of their useful lives. In terms of the traffic safety services industry, it means continuing the development of more effective and longer lasting retro-reflective materials. This kind of effort also encompasses developing, testing, and deploying newer and better retro-reflective devices, something that's an ongoing initiative of both government, academia, and industry. It's interesting to see how they're making road signs to help you see better at night. You know, I was wondering why they are so easy to spot, even though my eyesight is going a bit. I'm definitely going to be more careful about messing around when I'm in a car with my buddies. Guess where I'm headed right now, to the car wash. I'll tell you what, next time I go jogging at night, you'll see me in one of these retro-reflective suits. Operating a motor vehicle at night, especially in adverse weather, brings with it some very serious responsibilities. As a driver, you need to make sure that your vehicle is in good operating condition, that you're alert, and not under the influence of alcohol or drugs, that you're being cautious by reducing your speed, and that you're familiar with how retro-reflective signs, markings, and roadway safety devices can help. All of this is based on one common goal, to make America's roads safer for everyone. For information about how retro-reflectivity helps nighttime driving, contact the U.S. Department of Transportation, Federal Highway Administration, or ATSA, the American Traffic Safety Services Association.