To what extent may highway investments shape population growth and land development? To answer this question, three decades of data were examined in the Virginia locations of Fairfax County, Spotsylvania County, and Newport News. In each location, a highway investment (or deliberate decision not to make such an investment) was proposed by some as an instrument for increasing, shaping, or decreasing population or development growth. The case study approach was used, considering Fairfax County's decision not to build Monticello and other freeways proposed in 1960s comprehensive plans, Spotsylvania's efforts to manage Route 3 traffic congestion, and Newport News' desire for the construction of I-664. By comparing what planners intended these transportation decisions to accomplish with what transpired, the adequacy of using highway investments to influence growth may be assessed. The results suggest that in many ways, transportation investments are a blunt policy instrument. They can and do affect short-term travel and longer term location choices, but it is difficult to use investments to manage growth precisely. In fact, in none of the three case studies were all planners' intentions realized: when planned roads were not built in order to stop growth, growth continued, and when roads were built to encourage development or redevelopment in a specific location, growth occurred elsewhere. Yet, the three case studies suggest several findings that, if applied to planning practice, can yield future plans that are more realistic: (1) view transportation improvements in a supply/demand context; (2) quantify expected impacts where possible; (3) give transportation plans a realistic implementation mechanism; and (4) present forecasts as ranges rather than point values. Although these practices may be "common sense," their explicit consideration may facilitate planning efforts in the short run. However, an unintended consequence of reviewing the case study histories is that they strongly suggest Virginia counties have limited options for managing growth. To some extent, counties can influence the specific location of growth and what type is attracted--but the case studies leave the impression that if the market is there to support growth, eventually it will come. Within Virginia's current legal environment, counties have limited options for how they can accommodate this growth.