1. Introduction
The Cruise Assist Systems is drawing expectations as a system that can effectively create safe and efficient road transportation by supporting vehicles on the road, and its introduction is being awaited around the world. To date, research in this area has focused on developing of automated cruising, primarily because of the clarity of the R&D goals involved. However, problems and doubts regarding the feasibility and social acceptance of such an Automated Highway System (AHS), have prompted the United States and European nations to move away from a headlong drive toward creation of such a system, infavor of development that follows a more orderly, measured succession of phases. Development efforts and demonstrations held in the past are introduced here.

2. History of Cruise Assist Systems Research & Development
R&D in Cruise Assist Systems dates back decades. Induction cable guided automatic driving systems based on steering control and guidance cable laid on the path was conceived in the 1940s. Development for practical application started in the 1950s. The technological achievements were handed down and commercialized as unmanned endurance test driving systems operated on automanufacturerÕs proving grounds. Development of autonomous driving systems not requiring a special road infrastructure also grew. In 1977, the Mechanical Engineering Laboratory in Japan developed the world's first intelligent vehicle based on machine vision technology.

Intelligent vehicle in 1977

This was followed by the development of the Personal Vehicle System (PVS) in Japan, Autonomous Land Vehicle (ALV) and Navigation Laboratory (NavLab) in the United States, and Versuchsfahrzeug futonome Mobiliaund Rechnersehen (VaMoRs) and Vision Technology Application (VITA) in Europe. For both guided and independent systems, there are many problems that must be resolved both technologically and socially to realize fully automated cruising.
The Ministry of Construction (MOC) began R&D on Advanced Road Traffic Systems (ARTS) in 1989. Joint research is being carried out in both the public and private sectors on?Lateral and Longitudinal Control System? in the area of Advanced Vehicle Control Systems (AVCS). Experiments with the Advanced Cruise-Assist Highway Systems (AHS) were conducted in 1995 on a test track at the Public Works Research Institute (PWRI). In 1996, a real-road feasibility test and demonstration was held on the Joshinetsu Expressway before its opening to the public. The following paragraphs discribe the various demos organized around the world between 1995 and 1999. This will be followed by an outline of the development history taken from the leading research efforts automated cruising technology R&D efforts, and recent case studies in smart cruise technology development.

3. Demos Held Around the World

4. Conclusion
From these summaries of demos conducted since 1995, it is evident that most were aimed at promoting technological development by proposing appealing future possibilities but not based on near-future commercialization. The Joint Tests demo scheduled for this year is part of the Smartway Project schedule and is aimed at study of the "seven services" for safety to be introduced in phases starting in 2003. As a demo aimed at early commercialization, it is vastly different in character and content than past demos, and its practicality is drawing interest from various sectors of society and the world.