In this study, we explained the definition of hazard, risk, safety and so on in order to apply “Safety Science” establishing in the field of Mechanical System Safety to the construction industry. In the mechanical field, “Inherently Safe Design” should be considered firstly as risk reduction measures in risk assessment. On the other hand, in construction industry, there are difficult situations to apply the inherently safety design of the construction process with health & safety because organisations taking charge of ordering, designing and building are totally different by each. An incident happened unfortunately under that situation in Japan and so we would like to show how important to consider the inherently safety design in that incident. In addition, we investigated the efforts and challenges in United Kingdom which has excellent outcomes in the health & safety of construction industry. The advantages in UK would be integrated into three points mainly from our investigations, first one is the roles and duties of clients, designers and contractors, second one is the system/structure of construction project, third one is sufficient educational institutions. Those activities are partially introducing into Japanese construction industry and then it would be very significant to establish the social system/structure that clients, designers and contractors should consider the inherently safe design of construction project with the health & safety together.

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 On expressways, it is important to execute appropriate traffic regulations with coherent bases (i.e. results of disaster occurrence forecasting) for ensuring users’ safety against slope disaster caused by rainfall. In this study, the authors propose methodology for establishment of traffic regulation standards in consideration of the two types of risks: i) risk that slope disaster occurs when a traffic regulation is not executed, and ii) risk that slope disaster does not occur when a traffic regulation is executed. Specifically, the joint occurrence probability of slope disaster and rainfall are statistically formulated with the past slope disaster data and exogenous/endogenous data. Furthermore, the two types of risks are quantified with the joint occurrence probability, and an optimization model is formulated for determination of optimal regulation standards which minimize the sum of the two types of risks. Lastly, the effectiveness of the proposed methodology is discussed by using the actual slope disaster records in an expressway section.

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 In the emergency response at the event of disaster, decision makers have to decide the actions immediately. As a means of improving the quickness of the emergency response, there is a concept that it is used for decision making that real time estimate of the eventual death toll.

 This study considers improving the method that estimate the eventual damage scale at the initial stage of the disaster by examining the function which reproduce the change with time of the number of deaths. In cases that updated many information in the initial stage of a disaster, it is possible to improve the damage prediction accuracy by adopting the hyperbolic tangent function as the function of reproducing the change with time of the number of deaths. In addition, this study considers how to use the estimate model to be able to estimate the damage scale at the initial stage of the disaster as early as possible. This estimate model can predict damage in a certain accuracy at the initial stage of a disaster by updating information more frequently.

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 In accordance with the Landslide Disaster Countermeasures for Landslide Disaster Prone Areas Act, which went into effect in April 2001, areas considered vulnerable to landslides are designated as a Landslide Disaster Alert Area and issuing warnings and evacuation recommendations is promoted when heavy rain is expected. Roads neighboring areas prone to landslide disasters may be designated as both a Landslide Disaster Alert Area and as a Road Zone. In such areas, both the warning and evacuation standards for landslide disasters and standards for expressway traffic regulation apply. And therefore, to satisfy both standards it is important for the road operator and government to work together and build an evacuation system considering the size of the damage and the features of the two standards. In this study we have indicated the points to note for road disaster prevention by studying expressway routes in six prefectures in Japan operated by the three companies of NEXCO (Nippon Expressway Company) and confirming how many areas fall under the two standards and how those areas will be affected by heavy rainfall, and by comparing and analyzing the effects of different precipitation patterns and other differences when rainfall and other criteria exceed both standards.

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 When road slopes are damaged by torrential rains, earthquakes and other disasters, the procedure is to secure basic traffic functions quickly by carrying out emergency repairs and then begin full-fledged repairs for recovery. Though the type of damage suffered varies depending on the disaster site, in most emergency repairs, simple methods such as building temporary guard fences or counterweight filling works are adopted. Because roads in service require a quick temporary recovery from road slope disasters, in many cases the work is carried out based on workers’ experiences gained from past works, and practical know-hows have not been made into systematic procedures. This paper sorts out some 30 years’ worth of accumulated data on road slope disasters that occurred on expressways operated by the three NEXCO companies, groups the disaster patterns, and shows the flow from emergency repair to full-fledged recovery works per pattern. Points to keep in mind are noted so that they may be utilized in the actual emergency recovery works.

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