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U. Glaeser

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Support of Safe Driving System<br />

The support of safe driving system that appears in Fig. 38.5 is defined as the third development field of<br />

Japanese ITS has also been developed in Japan. In the early stages of the safe driving system, automatic<br />

driving was considered an ultimate support system. But many technical demonstrations on automatic<br />

driving from 1996 to 2000 gave people an impression that there were still many issues to be deployed from<br />

the point of view of both drivers and legal aspects. The author will demonstrate this more specifically later.<br />

So, recently it appears to the author that the idea of automatic driving is disappearing gradually. Instead<br />

of this, various warning systems and assistance systems have been considered. Demo2000 held at Japan<br />

last year shows effectiveness of those assistance systems such as AHS-I and ASV. “I” in the term of AHS-I<br />

means “information provision.” AHS-I is a kind of concept to assure safe driving of vehicle by using<br />

information provision of both traffic information and road configuration through road-to-vehicle communication.<br />

Not only road-to-vehicle communication but inter-vehicle communication is also useful to<br />

ensure traffic safety. A demonstration showing the effectiveness of this technology was also shown in<br />

Demo2000 at Tsukuba, Japan. For example, it was shown to form platooning composed of running vehicles<br />

using inter-vehicle communication technology.<br />

38.4 Issues of ITS Development and Roles<br />

of Software Technology<br />

Issues of ITS Development<br />

The readers can easily think of technological issues to put into practical with the use of ITS, particularly<br />

an assist system of safe driving. Actually, the more important issues to deploy ITS are related to social,<br />

legal, and human issues, including responsibility, which are recognized with technical demonstration<br />

from 1996 to 2000 of the support system for safe driving. Table 38.5 shows the technical issues for<br />

deploying ITS. The importance of these technical issues will be easily understood. Figure 38.16 shows<br />

social, legal, and driver’s issues summarized by Becker and the author.<br />

Legal and driver’s issues are composed of five terms, as shown in Fig. 38.16. The first is “product<br />

perception and use.” This means how deeply users of the ITS-related system like the assist system for<br />

safe driving, can recognize the performance and the use of the system. For example, suppose you buy<br />

an air-bag system. You have to understand both its performance and how to use it very well. You have<br />

to know how it works depending on magnitude of the crash. If you do not know that, you will be<br />

overconfident about the air-bag system, and you may be injured by a traffic accident. In this process,<br />

sufficient explanation of a system by a salesman is very important for users to operate the system very well.<br />

The second important issue is about “system safety and controllability” in Fig. 38.16. One can easily<br />

understand the importance of this issue if one compares control systems of a car with that of an aircraft.<br />

Pilots in an aircraft can operate the control system completely because pilots know how the control<br />

© 2002 by CRC Press LLC<br />

TABLE 38.4<br />

Specification of DSRC<br />

Item Description<br />

Frequencies Two pairs in the 5.8 GHz band<br />

Bandwidth 8 MHz max.<br />

Transmitter output 10 mW<br />

Communication system Active type with slotted Aloha<br />

Maximum vehicle speed 80 kph<br />

Data transmission rate 1.024 Mbps<br />

Modulation method Amplitude shift keying<br />

Bit error rate Less than 10 ppm<br />

Communication error rate Less than 1 ppm<br />

Encoding method Manchester encoding

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