The Minimum Revenue Guarantee (MRG) was designed to mitigate the financial risk of private investors that participate in the transportation project as concessionaire under a public-private partnership (PPP) program. The MRG can pose a significant financial burden to governments especially when the contract revenue is set considerably higher than the actual revenue. This may encourage the concessionaire to inflate the traffic forecast to make the project look as if it will be profitable. In order to mitigate this problem, extra conditions for exercising the MRG can be considered. This study examines how these exercise conditions change the economic value of the MRG using the case study based on the urban railway project in the Republic of Korea. By utilizing the real options analysis, the study identified that the exercise conditions have worked to curtail the expected payment from the government, eventually leading to a reduction in the concessionaire’s expectation of revenue. The value of MRG was at a far lower level compared to the concessionaire’s investment because of the low probability of exercising the MRG when the exercise conditions apply. The findings are expected to contribute to the sustainability of the PPP program by recognizing and quantifying liabilities and risks embedded in the concession agreement in advance.

Various risk factors influence the success of public–private partnership (PPP) projects. This study analyzes the risk attributes of PPP projects and develops a regression model based on a 20-year PPP project database to quantitatively analyze the factors affecting the contracted internal rate of return (CIRR) of PPP projects. Although the risk factors of PPP projects have been widely studied, the factors affecting CIRR have not been explored. Information from the intra-info DB system managed by Korea Development Institute was used to calculate the impact of the variables on CIRR. It was observed that the CIRR of Korea’s PPP projects did not reflect the risks associated with the facility types, service area, amount of private investment, and operation period accurately. Financing costs did not demonstrate a statistically significant relationship with the CIRR either. Furthermore, the CIRR of projects with a minimum revenue guarantee option was found to be higher than that of projects without. The CIRR of the current project was found to be closely related to the number of bidding competitors and the CIRR values of previous projects that are similar to the current one. This is attributed to a failure in the bureaucratic negotiation behavior of the parties due to their avoidance of responsibilities.

Walking has been highlighted as an independent transportation mode as well as an access/egress mode to/from public transit to encourage the use of more sustainable transport systems. However, walking does not seem to have priority over other transportation modes, especially in areas where various modes of movement are in conflict. The pedestrian push-button system seems to be a solution to distribute the right of way. The focus of this study is on the performance issue of the pedestrian push-button. Specifically, this study deals with issues related to mid-block crossings and attempts to answer two questions: whose waiting time is longer at pre-timed and push-button crossings, pedestrians, or vehicles? and which system – pre-timed or push-button – is better in terms of total waiting time? According to our simulation analyses, if the pedestrian flow rate is less than 120, 85, and 70 ped/h for two-, three-, and four-lane roads, respectively, the push-button system is recommended.

In this paper, a methodology for accelerating the double-projection method designed for the asymmetric traffic equilibrium assignment problem is proposed. One of the factors that determine the efficiency of the projection method is a properly selected step size. This study customized the step size for each origin-destination (O-D) pair by formulating the assignment problem on the space of path flows. In addition, even if the transportation network is decomposed into each O-D pair, the step size based on the entire path flows is also available. The study developed a step-size selection strategy with two different available step sizes obtained from different spaces of path flows vectors. During the projections of path flows for each O-D pair, the strategy compares the step size customized for that O-D pair and the one from the entire path flow vectors and selected a bigger step size. Several numerical tests have been conducted on various sized networks and convergence criteria. The methodology consi...