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In dense fog, adequate visibility of the delineator is important for providing the driver with road geometry cues. A new illuminated delineator that uses laser beams is proposed. Very few data have been published with regard to the visibility of laser beams in fog. However, laser beams can be expected to be highly visible in dense fog because of their high intensity, high energy, and directivity that is both monoclinic and strong. A study was conducted to evaluate the visibility of laser beams in fog. The effectiveness of two types of laser heads and an illuminated delineator containing two 10-W glow lamps was investigated in artificial fog. The dependent variables were luminance at a specific point on the laser beam and estimated brightness. The major independent variables were fog density and illuminance in the observation room. The laser beams were observed as sharp lines of light in dense fog. The visibility of the laser beams in fog had an inverse relationship to that of normal light. In addition, subjects reported that the directivity of the laser beams could effectively indicate the direction of the highway. However, the visibility of the laser beams was strongly affected by the illuminance in the observation room, and care must be taken to prevent drivers from looking directly at redundant laser beams. On the basis of these results, it is concluded that laser beams may be useful lighting sources in dense fog if this safety problem can be overcome.

This paper aims to consider the influence of technique for the children's sensibility by comparison and analysis models made by different constructional way; "tying" and "jointing". As the method, we held a workshop of modeling a "secure house" at 1/20 scale with the third graders of primary school, and they made models with "tying" and "jointing" respectively. After the workshop, the children drew their models with explanations. As the analysis, we morphologically analyzed the models by the floor levels and the structure types, and semantically words with KJ method. As a result, in "tying", as more primitive construction technique, its most important facility was a bed to sleep. On the other hand, in "jointing", as more sophisticated technique, their adventurous sense has increased. That is, the difference of constructive technique evokes the sensual duality of security and adventure.

Japan uses its limited land area intensely and many businesses are located along roads. Because of insufficient regulations in Japan, advertising signs such as billboards are more prevalent there than in Europe and America. Road signs, therefore, are more difficult to recognize, because they may be hidden among such commercial and other signs. The amount of information along roads that is not required for driving, such as billboards and signs on electric poles, is measured and the detectability of road signs is investigated quantitatively through actual road tests. The ratio of area of clutter signs to the total area of the field of view was called the visual noise ratio. Investigation of the relationship between the distance at which a driver first recognized a highway number sign and the visual noise ratio revealed a negative correlation. Differences between the sexes were also observed; for example, female drivers were less affected by the visual noise ratio, but their absolute visible distances were shorter than those of male drivers.