Evaluating the Role of Private Investment in Infrastructure Assets.

摘要

Public Private Partnership (P3) projects are likely to fundamentally impact entire transportation systems. However, most studies are focused on system modeling rather than policy analysis, and few studies have examined the impacts of P3s on real-size transportation networks. Policy guidance for devising and administering P3 contracts to improve transportation system performance while maintaining profitability is lacking. Using the transportation network of Fresno, a middle-sized city in California as an example, this study considers alternative P3 approaches for profit maximization and system cost minimization at full urban transportation network scales. Based on system modeling results, we offer the following recommendations for policy makers to design and promote successful P3 projects in urban environments: (1) to promote a profitable and a socially beneficial system, toll rates should be set between profit-maximizing and system-optimal rates; (2) even though tolls (i.e., higher travel costs) on a few roads helps reduce travel demand they may, counter-intuitively, lead to higher total travel cost for the transportation system as a whole; (3) lower limit(s), in addition to upper limit(s), for tolls may be required to enforce system-optimal tolling and avoid undercutting; (4) a variable tolling scheme (i.e., temporally and spatially varying tolls) significantly reduces congestion and increases profits relative to flat tolls; and (5) public officials should provide a comprehensive plan regarding past, current, and future P3 projects along with detailed system-wide impact analysis of project implementation in order to promote a more sustainable transportation system.