The process of research, development, and acquisition to procure military vehicles has historically been challenging for a variety of reasons. Sometimes, the difficulty lies in translating the threat (such as an enemy antitank guided missile) into a design criterion (such as a protection requirement of so many inches of armor plating). In other instances, problems have included a mismatch between cost estimates and actual costs, creeping or changing requirements, unrecognized risks from immature technologies, or overly ambitious designs. In Section 222 of the National Defense Authorization Act for Fiscal Year 2010 (Public Law 111-84), Congress directed the Secretary of Defense to contract with an independent body to assess activities for modernizing the technology of the ground combat vehicle and armored tactical wheeled vehicle fleets. RAND's National Defense Research Institute was asked to conduct the study and, specifically, to provide a detailed discussion of requirements and capability needs, identify capability gaps for vehicles, identify critical technology elements or integration risks associated with particular categories of vehicles and specific missions, and recommend actions to address the identified capability gaps. The research focused on a selected group of ground combat and tactical wheeled vehicles that are representative of different classes of vehicles (e.g., heavy truck, main battle tank) and that were at different stages of development. These include the Army's ground combat vehicle (GCV); the joint light tactical vehicle (JLTV), which is sponsored by the Army, Marine Corps, other services, and foreign partners; the Marine Corps' expeditionary fighting vehicle (EFV) and medium tactical vehicle replacement (MTVR); and the Army's Heavy Expanded Mobility Tactical Truck (HEMTT).