Project teams expend substantial effort to develop scope definition during the front end planning phase of large, complex projects, but oftentimes neglect to sufficiently plan for small projects. An industry survey administered by the author showed that small projects make up approximately half of all projects in the infrastructure construction sector (by count), the planning of these projects varies greatly, and that a consistent definition of “small infrastructure project” did not exist. This dissertation summarizes the motivations and efforts of Construction Industry Institute (CII) Research Team 314a to develop a non-proprietary front end planning tool specifically for small infrastructure projects, namely the Project Definition Rating Index (PDRI) for Small Infrastructure Projects. The author was a member of CII Research Team 314a, who was tasked with developing the tool in September 2015. The author, together with the research team, scrutinized and adapted an existing infrastructure-focused FEP tool, the PDRI for Infrastructure Projects, and other resources to develop a set of 40 specific elements relevant to the planning of small infrastructure projects. The author along with the research team supported the facilitation of seven separate industry workshops where 71 industry professionals evaluated the element descriptions and provided element prioritization data that was statistically analyzed and used to develop a corresponding weighted score sheet. The tool was tested on 76 completed and in-progress projects, the analysis of which showed that small infrastructure projects with greater scope definition (based on the tool’s scoring scheme) outperformed projects with lesser scope definition regarding cost performance, schedule performance, change performance, financial performance, and customer satisfaction. Moreover, the author found that users of the tool on in-progress projects agreed that the tool added value to their projects in a timeframe and manner consistent with their needs, and that they would continue using the tool in the future. The author also conducted qualitative and quantitative similarities and differences between PDRI – Infrastructure and PDRI – Small Infrastructure Projects in support of improved planning efforts for both types of projects. Finally, the author piloted a case study that introduced the PDRI into an introductory construction management course to enhance students’ learning experience.