 that in the next 10 years, 500,000 people will die on highways in the United States alone. The losses, due to death, injury, and property damage, will exceed $1 trillion. Don't you wish there was a systematic way to identify and solve highway safety problems? Well, there is. It's called Highway Safety Improvement Program Management. This management system is covered in three IRF videotape programs. This one, plus evaluating and selecting the best safety alternatives and evaluating safety program results. This is Bill Grenke. He is a safety engineer with the State Highway Department. He is just now reading about a Highway Safety Improvement Program Management System. According to the National Cooperative Highway Research Program Report he is studying, this system will identify real problems instead of perceptions. The solutions will be cost-effective, and in the event of legal actions, the existence of the system will aid the defense. Naturally, Bill is a bit skeptical. He has dealt with highway safety for years. He knows motor vehicle movements involve a complex set of interrelationships between drivers, vehicles, and the roadway. Many situations, including fatigue, bald tires, potholes, and blowing dust, can affect the driver's ability to respond to an emergency situation. Combining these variables with high traffic volume increases the complexity. When one or more of these situations arise, accidents may occur. Sorting out what causes the accidents and what can be done to prevent them in the future is the challenge of highway safety professionals. Bill is used to considering improvements that affect the stages of an accident. Pre-crash, crash, and post-crash. Pre-crash improvements aim at reducing the frequency of accidents. Crash and post-crash improvements aim at reducing the severity of accidents. These improvements involve the roadway, the vehicle, and the driver. The systematic approach Bill is reading about addresses the roadway category. Highway safety improvement program management has six phases. They are phase one, identify safety problems. Phase two, identify alternative improvements. Phase three, evaluate alternatives and select improvements. Phase four, develop and implement the highway safety improvement program. Phase five, evaluate each safety improvement. And phase six, evaluate overall safety program. There are four steps involved in phase one, identify safety problems. Step one is to identify hazardous locations. A location is either a spot along the road or an intersection. There are two ways Bill can make his determination. He can use accident data analysis, which requires at least one year of historical data on highway accidents. Using computer records and analysis programs, he can compare accident location information. Or he can use conflict analysis. That requires visual identification of areas with indications of hazardous conditions, such as frequent skid marks. It may also mean doing intersection turning analysis. These methods, of course, are not as accurate as accident data analysis. Bill may have to use them when accurate historical accident data is not available. The next step in identifying safety problems is analyzing and ranking the locations. There are several possible methods he can use. One is the number method, which means he must plot a year's worth of accidents on a road map. Then he can easily identify locations with the largest cluster of accidents. This method is good in small jurisdictions with low numbers of accidents. The number method does not consider accident rates, so there is also the rate method. If Bill identifies different locations with the same number of accidents, but one has substantially more traffic than the other, then he needs to show that the location with less traffic is more hazardous. Using the rate method, he can prove it. He divides the number of accidents at a location by the number of vehicles approaching the location in millions, giving a rate of occurrence expressed as annual accidents per million vehicles. R is the accident rate at the spot or intersection in annual accidents per million vehicles. A is the number of accidents during the time period. T is the time period, usually 365 days. And V is the traffic volume approaching the spot or intersection in vehicles per day. Another method Bill can use is the rate quality control method. Research has shown that accident occurrence follows a statistical pattern known as the Poisson distribution. Using another formula, Bill can identify locations with a critical accident rate, an accident rate that is above normal. In this formula, R sub C is the critical accident rate in annual accidents per million vehicles. R sub A is the system-wide average accident rate for a specific type of road in annual accidents per million vehicles. M is the vehicle exposure in millions of vehicles per year. And K is the constant that establishes the level of confidence. Then by subtracting the critical rate, R sub C, from the actual rate, R, he will come up with a quality control number, Q sub C. The computer can sort these rates in descending order. That will give Bill a list of hazardous locations ranked from the very worst to the least worst conditions. Step 3 of identifying safety problems is to compare the high accident location list with the current capital improvement program. If a hazardous location is already scheduled for improvement, Bill can take it off his location list. If a hazardous location has had recent improvements but is still a problem, Bill will leave it on the high accident list for more improvements. To finish out this phase of the program, Bill will prepare a report. It will list all the high accident locations from the most important on down, based on the quality control numbers. He will use this report in the next phase of analysis to determine the most appropriate improvement for each location. Let's look at that phase. In this phase, Bill will identify alternative improvements. There are four steps. Step one is to obtain accident data. Police file accident reports on most accidents. They should make them available to traffic engineers responsible for conducting safety studies. If report forms are designed and filled out properly, they will have the best information on the types and causes of accidents at specific locations. His next step is to analyze the accident data. As he categorizes the accidents, he'll discover patterns that will help him determine the causes of accidents at that location. There are forms available that break accidents into groups. Now it's time for Bill to do a field investigation. He will look for one or more improvements that could be made to each location. He should ask himself, are there blind corners? Are signs and signals easy to understand? Is the channelization clear? What about parked cars and advanced warning signs? There are worksheets available to help with this effort. Bill is an experienced traffic engineer, so he will probably come up with at least one improvement for each location. As he prepares to make recommendations, he must remember there are four increasingly complex ways of dealing with a hazardous location. The first is to do nothing. This is usually not acceptable, but must be considered as an alternative nonetheless. The second alternative is to modify the location. That could mean replacing rigid signs with breakaway ones, or putting in a median barrier. The third alternative is to change the flow of traffic. That could mean reducing the speed limit, putting in turn signals, improving signs, or adding pavement markings. The fourth alternative is to eliminate the hazard altogether. This is usually done through construction of a grade separation, or some other major improvement project. Now Bill is ready for the fourth and final step in this phase, a report on his findings. For each location, he should indicate the types of accidents, their probable causes, and the alternative improvements to the location. Through a logical and systematic process, our friend Bill is finding out that he can identify a series of alternatives. In this program, we followed traffic engineer Bill Grenke, as he learned about a systematic approach to highway safety improvement program management. It has six phases. They are, phase one, identify safety problems. Phase two, identify alternative improvements. Phase three, evaluate alternatives and select improvements. Phase four, develop and implement the highway safety improvement program. Phase five, evaluate each safety improvement. And phase six, evaluate overall safety program. Phase one involves identifying hazardous locations. There are two ways Bill can make his determination. He can use accident data analysis, or he can use conflict analysis. That requires visual identification of areas with indications of hazardous conditions, such as frequent skid marks. The next step in identifying safety problems is analyzing and ranking the locations. There are several possible methods he can use. One is the number method, which means he must plot a year's worth of accidents on a road map. The number method does not consider accident rates, so there is also the rate method. Another method Bill can use is the rate quality control method. Research has shown that accident occurrence follows a statistical pattern known as the Poisson distribution. Step three of identifying safety problems is to compare the high accident location list with the current capital improvement program. If a hazardous location is already scheduled for improvement, Bill can take it off his location list. If a hazardous location has had recent improvements, but is still a problem, Bill will leave it on the high accident list for more improvements. To finish out this phase of the program, Bill will prepare a report. It will list all the high accident locations from the most important on down, based on the quality control numbers. Phase two is developing alternative improvements. Step one is to obtain accident data. Police file accident reports on most accidents. They should make them available to traffic engineers responsible for conducting safety studies. If report forms are designed and filled out properly, they will have the best information on the types and causes of accidents at specific locations. His next step is to analyze the accident data. As he categorizes the accidents, he'll discover patterns that will help him determine the causes of accidents at that location. Now it's time for Bill to do a field investigation. He will look for one or more improvements that could be made to each location. He should ask himself, are there blind corners? Are signs and signals easy to understand? Is the channelization clear? What about parked cars and advanced warning signs? As he prepares to make recommendations, he must remember there are four increasingly complex ways of dealing with a hazardous location. The first is to do nothing. The second alternative is to modify the location. The third alternative is to change the flow of traffic. The fourth alternative is to eliminate the hazard altogether. Now Bill is ready for the fourth and final step in this phase. A report on his findings. For each location, he should indicate the types of accidents, probable causes, and the alternative improvements to the location. Through a logical and systematic process, our friend Bill is finding out that he can identify a series of alternatives. Picking the best alternative for each location is the purpose of the next phase. That phase and the ones following it are covered in two more IRF videotapes in this series. For more information on this or other IRF videotapes, write to the International Road Federation or call the numbers on your screen.