ACHIEVING LONG-TERM SUSTAINABILITY OF NON-TOLL ROAD BRIDGES WITH AN ALTERNATIVE PPP CONTRACT METHOD

Abstract

 Many of Japan's public roads were constructed during the period of high economic growth and are aging. The maintenance and management of bridges, in particular, is a pressing issue. Public-private partnerships have been attracting attention in the field of infrastructure maintenance and management, although concession schemes are not applicable to non-toll roads.

 In this study, a PPP project for non-toll road bridges is assumed, and a model is developed assuming that the operator repairs and renews bridges at its own discretion and the government pays according to the condition of the bridges. The results show that it is possible to encourage operators to voluntarily perform preventive maintenance by setting a payment scheme. In addition, a trade-off between the performance when the deterioration prediction is accurate and the robustness against the inaccuracy of the deterioration prediction is shown.