Tham khảo tài liệu 'intelligent vehicle technology and trends episode 1 part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 2 Introduction injury-producing crashes over four million crashes resulting in property damage and an estimated 10 million crashes total on an annual basis. Over 100 people die every day on average. Road crashes consume a greater share of national heath care costs than do any other single cause of illness or injury in fact the . Department of Transportation has estimated the overall societal cost of road crashes annually in the United States at greater than 230 billion 4 . Furthermore human limitations in sensing and control of individual vehicles multiplies when hundreds or thousands of vehicles are sharing the same roads at the same time leading to the all too familiar experience of congested traffic. Traffic congestion undermines our quality of life in the same way air pollution undermines public health. Sources of air pollution have been attacked with a wide variety of government policies and new technology why has the same not occurred with traffic congestion The answer lies in the fact that traffic flow consisting of cars controlled by people is doomed to inefficiency due to our very human aspects of delayed response to traffic conditions. When we detect brake lights ahead time is expended as we assess the situation and proceed to apply our own brakes if needed. When traffic ahead accelerates a similar lag time is incurred to sense that condition and follow suit. The aggregate effect of these factors creates accordion effects or shock waves in dense traffic flows as well as the relatively slow clearance time for intersections controlled by traffic signals. Traffic congestion is also caused by the sheer volume of vehicles attempting to use roadways exceeding physical capacity limitations. Around 1990 road transportation professionals recognized the emergence of affordable information computing and sensor technologies and began to apply them to traffic and road management. Thus was born the intelligent transportation system ITS . Starting in the late 1990s .
