This chapter examines the problems that arose during the planning and development of three corridor cities in Montgomery County: Rockville, Gaithersburg, and Germantown. The idea of corridor cities melded the interests of Montgomery's miniature and commercial republics—a rare consensus in land use policy. According to the General Plan, Rockville, Gaithersburg, and Germantown would each be developed as a complete, compact “new town.” The chapter considers the opposition of the municipalities of Rockville and Gaithersburg to the idea of becoming corridor cities and how the problem of many governments obstructed development in accord with the General Plan (although Rockville eventually evolved in a way close to the vision). Germantown presented a different problem, that of many builders without a coordinating master developer. Rockville, Gaithersburg, and Germantown offer lessons on the effectiveness and limitations of using infrastructure extension and regulations to manage the pace and character of development.