In 2011, light rail transit (LRT) in eight U.S. metropolitan areas—Phoenix, Arizona; Sacramento and San Diego, California; Denver, Colorado; Saint Louis, Missouri; Portland, Oregon; Dallas, Texas; and Salt Lake City, Utah—carried 20% or more of the metropolitan area's total fixed-route ridership. The study reported in this paper explored the role of socioeconomic, planning, and operational factors as influences on LRT and metropolitan fixed-route performance in these eight areas, where LRT might function as a backbone around which other transit services were organized. Of particular interest were the planning and operational decisions over which planners and policy makers exercised some control. With the use of a combination of national and agency data, the eight areas were ranked on criteria with a basis in the optimal conditions suggested by a review of the literature. These rankings were then related to performance. The results showed that although socioeconomic factors were important influences on performance, they were not determinative. Planning and operational decisions about coverage, access, and multimodal coordination and integration also emerged as important influences on LRT and metropolitan transit performance.