In Japan, it became necessary to address the issue of traffic accidents in the 1960s, when traffic accidents increased rapidly with the spread of motorization within the nation. The need for driving simulators as a tool to tackle the problem was recognized, and a government-led development effort began. Manufacturers followed with their own efforts to develop driving simulators to aid in research of steering and stability. We introduce the history of hardship from the times when the technologies for display and motion systems developed for flight simulators were not readily usable for driving simulators.

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Longitudinal vehicle control and/or warning technologies that operate in accordance with drivers' subjective perception of risk need to be developed for driver-support systems, if such systems are to be used fully to achieve safer, more comfortable driving. In order to accomplish this goal, it is necessary to identify the visual cues utilized by drivers in their perception of risk when closing on the vehicle ahead in a car-following situation. It is also necessary to quantify the relation between the physical parameters defining the spatial relationship to the vehicle ahead and psychological metrics with regard to the risk perceived by the driver. This paper presents the results of an empirical study on quantification and formulization of drivers' subjective perception of risk based on experiments performed with a fixed-base driving simulator at the Nissan Research Center. Experiments were carried out to investigate the subjective perception of risk relative to the headway distance and closing velocity to the vehicle ahead using the magnitude estimation method. The experimental results showed that drivers' perception of risk was strongly affected by two variables: time headway, i.e., the distance to the lead vehicle divided by the following vehicle's velocity, and time to collision, i.e., the distance to the lead vehicle divided by relative velocity. It was also found that an equation for estimating drivers' perception of risk can be formulated as the summation of the time headway inverse and the time to collision inverse and that this expression can be applied to various approaching situations. Furthermore, the validity of this equation was examined based on real-world driver behavior data measured with an instrumented vehicle.

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Backing up tractors with trailers is a difficult task since the kinematic behavior of articulated vehicles is complex and hard to control. Especially unskilled drivers are overstrained with the complicated steering process. To learn and practice the steering behavior of articulated vehicles, we developed a 3D driving simulator. The simulator can handle different types of articulated vehicles like semi-trailers, one- and two-axle trailers, or gigaliners. The use of a driving simulator offers many advantages over the use of real vehicles. One of the main advantages is the possibility to learn the steering behavior of all vehicle types. Drivers can be given more and better driving instructions like collision warnings or steering hints. Furthermore, the driver training costs can be reduced. Moreover, mistakes of the student do not lead to real damages and costly repairs. The hardware of the simulator consists of a low cost commercial driving stand with original truck parts, a projection of the windshield and two flat panel monitors for the left and right exterior mirrors. Standard PC hardware is used for controlling the driving stand and for generating the realtime 3D environment. Each aspect of the simulation like realistic vehicle movements or generation of different views, is handled by a specific software module. This flexible system can be easily extended which offers the opportunity for other uses than just driver training. Therefore, we use the simulator for the development and test of driver assistance systems.

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This paper investigates effect of AHS (Advanced Cruise-Assist Highway Systems) service using VICS (Vehicle Information and Communication System) on driver behavior and safety awareness, through experiment with a driving simulator. In this AHS service, when drivers of vehicles behind do not notice an incident such as stopping vehicle or rearmost congestion at blind curve sections of urban expressway, 3-media VICS-enable in-vehicle navigation unit provides them information to avoid collision based on communication between road and vehicle. In this study, such road environment and traffic condition around drivers were generated by using a motion-based driving simulator which had a real car body, seven 150-inch screens covering 330-degree field of view, 3-media VICS-enable in-vehicle navigation unit in the cockpit. Twenty-nine subjects were participated and instructed to perform based on their usual safe driving skill in urban expressway. Three types of visual content of AHS information were examined from the viewpoint of driving maneuver, visual behavior and safety awareness. Subjective evaluation was also conducted in terms of understanding of information, surprise and maneuver. The results of the experiment indicate that AHS service is more effective to decrease possibility of collision than usual driving without AHS service, in terms of timing of releasing accelerator pedal, applying brake pedal and improvement of safety awareness, although it was observed that understanding of AHS information varied among the subjects. Especially, based on the result of this study, simple figure of AHS information is more effective than text message in order to avoid such a collision safely.

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This paper investigates effects on driver's eye movement when the driver is distracted by a secondary cognitive task that demands a high mental workload. By observing drivers behavior in a fixed-base driving simulator, we analyze how the time lengths of eye fixations change when a driver is imposed to perform a cognitive secondary task. The results show that two types (Type 1: the number of short fixations increases, Type 2: the number of short fixations decreases) are found. Interestingly, our data show that both types can be seen even in one driver depending on traffic conditions. It is also shown that likelihood of occurring Type 1 or Type 2 effects depends on driver. The data suggest that it is possible to predict which effect is likely to occur for a driver if we analyze his or her eye movement under normal conditions. With these findings, this study developed and improved a driver-adaptable algorithm for detecting the state of being under high mental workload. The results suggest that the time length of an eye fixation can be useful index at least several drivers.

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This paper reports results of an experiment with a driving simulator in order to answer the following question: What type of support should be given to an automobile driver when it is determined, via some monitoring method, that the driver's situation awareness may not be appropriate to a given traffic condition? This paper compares (a) warning type support in which an auditory warning is given to the driver to enhance situation awareness and (b) action type support in which an autonomous safety control is executed as a soft protection for avoiding an accident. Although the both types of driver support are effective, the former sometimes fail to assure safety, which suggests a limitation of the human locus of control assumption, while efficacy of the latter may be degraded by an incorrect human reasoning that can happen under uncertainty. This paper discusses viewpoints needed in the design of systems for supporting drivers in resource-limited situations in which information or time available for a driver is limited in a given traffic condition.

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This paper describes forward-collision warning system adapted for individual driver characteristics. Conventional forward-collision warning system has the problem to output warning signals excessively though the driver intends to stop the vehicle. The driver feels irritated by these useless warnings. The objective of this study is to develop an algorithm which solves this problem. In this algorithm, the warning output timing is determined to a value that the driver conducts braking action for possible collision avoidance when looking aside. In addition, the warning output timing is changed by foot position of the driver. From experimental result by young and elderly subjects using driving simulator, excessive output of warning signal was reduced without collision.

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A road alignment which has a long straight section followed by sharp curve is dangerous, because drivers have the habit to accelerate on the long straight section and then accidents occur on the short curve as the result of speeding. This study evaluated the alternatives to speed humps in order to reduce speed safely and comfortably on roads with this incorrect road alignment. There are several speed control facilities to reduce speed on roads with wrong road alignment. The speed hump is dangerous at high speeds because drivers must reduce speed rapidly and because of the physical impact. The image hump provides less effect for drivers who already know of its presence. So, to resolve these matters, we propose a new type of speed control facility. An image hump with transverse grooving will be effective in reducing speed because the transverse grooving gives vibration and noise to drivers who are already aware of the presence of the image hump, but it does not give the hard physical impact to vehicles. The study on the effect of the alternatives to speed humps was carried out using the K-ROADS (KICT-Road Analysis Driving Simulator) which has been developed to analyze and evaluate road safety at the project HuRoSAS (Human & Road Safety Analysis System) since 2003. K-ROADS has two distinct functions. One is the visual system which has a 360 degree F. O. V. to reduce dead angles on black spots such as at-grade intersections. The other is the motion system which has high frequency vibration to reproduce vibrations made in irregular road surfaces. This study found out that the image hump with transverse grooving is a safe speed control facility in order to reduce driving speed safely and comfortably on a straight section followed by a sharp curve, even if drivers are known the existence of image hump.

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