Multimodal public-private partnership (MP3) projects denote transportation investments that serve two or more modes and include substantial private sector involvement. Because nonauto modes often require an operational subsidy, MP3s can be rare; thus, implementation of such projects is of interest. This study reports on the results of interviews regarding U.S. agencies’ pursuit of 23 candidate MP3 projects. For example, when a decision is made to pursue a multimodal project as a P3, the reason is frequently to obtain private financing. Other reasons are construction speed, expertise in specific areas such as land development, and an enhanced ability to relate monies paid to the quality of transit provided. Further, when transportation modes are being added to a P3 project, revenue is a reason for only a minority of projects: other reasons included multiple modes being a part of the region’s long-term vision, public opinion, and the project being inherently multimodal (e.g., redevelopment of an area supporting rental car parking and commuter rail). In most decisions regarding MP3s, land impacts are considered to some degree, but the reasons vary: no expected impact, more intense development in a particular location, impacts near the facility but no exact location pinpointed, and increased real estate values. The conditions supporting an MP3 are diverse and include the implementation of a region’s long-term vision, public pressure, and a unique opportunity to bring together stakeholders to create a project that was otherwise infeasible or to solve a specific problem. Accordingly, as reported in this study, their diverse nature means that MP3s can be considered at multiple decision points in the project development process.

多式联运的公私合营（MP3）项目表示为两种或多种方式提供服务的运输投资，其中包括大量私营部门的参与。由于非自动模式通常需要可操作的补贴，因此MP3很少见。因此，执行此类项目很有意义。这项研究报告了有关美国机构追求23个MP3候选项目的采访结果。例如，当决定将多模式项目作为P3进行时，其原因通常是获得私人融资。其他原因包括施工速度，在特定领域（例如土地开发）的专业知识以及将支付的款项与所提供的过境质量相关联的能力增强。此外，在将交通运输方式添加到P3项目中时，收入仅是少数项目的原因：其他原因包括多种模式成为该地区的长期愿景，公众舆论的一部分，并且该项目本来就具有多种模式（例如，对支持租赁停车场和通勤铁路的区域进行重新开发）。在大多数有关MP3的决策中，都会在一定程度上考虑土地影响，但是原因各不相同：没有预期的影响，在特定位置的发展更为激烈，在设施附近产生的影响但没有确切的位置以及房地产价值的增加。支持MP3的条件各不相同，包括实施该地区的长期远景规划，公众压力以及一个独特的机会，可以使利益相关者聚集在一起，以创建原本不可行或解决特定问题的项目。因此，如本研究报道，