JR East has been made start as a new railway company in line with the reform policy of the Japan national railway in 1987. Along with it, JR have beam required the management emphasizing on the efficiency and quickness as a private enterprise. On the other hand, construction companies have remarkably made progress on the construction technology in recent years. Under the circumstance, we tried to establish the construction cost estimates of the railway improvements utilizing the technical proposals based on high technologies by innovative construction companies. In conclusion, we obtained a construction cost reduction and process speeded by the number of technical proposals and we also had acquired the effect of quality and efficiency in the construction cost estimates.

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 In order to maintain and manage infrastructures appropriately under a budget constraint, it is necessary to grasp the processes of deterioration and damage, which are the targets of visual inspection, specify the criteria for risk management, and determine inspection cycle. This study is focused on the peeling/falling of the protective covering concrete of expressway bridge slabs, formulates its process with the Poisson model, and proposes a model that can take into account some effects on peeling/falling. This study proposes a random proportional Poisson model for discussing the heterogeneity of the peeling/falling of concrete of individual slabs. Then, the criteria for risk management regarding peeling/falling are specified, and a method for determining optimal inspection cycle that satisfies the criteria for risk management is proposed. Lastly, the appropriateness of the proposed model is discussed empirically, by applying it to actual expressways.

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 Value Engineering (VE), one of the effective management techniques to provide products and services, is focused as a measure to reduce the cost on public works, but its effectiveness as a management technique doesn't seem to be fully understood in the construction industry.
 This paper demonstrates aspects and issues of VE in construction industry by comparing with manufacturing industry, and to combat these, VE which is implemented in construction industry must be succinct and proposes methods to conduct it from the viewpoint of construction industry.
 At last, the place to go to for construction industry down the road regarding the VE adaptation is clarified.

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 In this study, the methodology to evaluate a road riding comfort was proposed by using biological pulse wave. The road riding comfort was defined by Lyapunov exponent calculated from biological pulse wave of driver and passenger during vehicles running. Through some experiment, it was found that the biological pulse wave was effective as the way of adopting human sensuous evaluation in order to estimate influence of the road riding comfort. And how to use the road riding comfort index was examined for road asset management. It could confirm that the riding comfort of every road could be distinguished by using biological pulse wave relatively.

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