Pros and cons of various mature Automated Highway Systems (AHS) have been a subject of intense study. However, such discussions are nothing but intellectual exercises unless the issue of how to evolve, in a planned and managed fashion, the current highway systems towards these mature AHS is also addressed. Since full functionality of a mature AHS cannot be realized suddenly, discrete functional steps must be identified and optimized. This paper defines an evolutionary stage towards a mature AHS as any discernible functional increment whose realization may encounter considerable difficulties requiring a significant amount of conscious effort to overcome. A good evolutionary scenario consists of stages each of which provides sufficient additional functionality that justifies the required effort to overcome the associated difficulties. Six dimensions of deployment difficulties are identified: technology, infrastructure, human factors, vehicle manufacturing and mainlenance. insurance and public will. An illustrative evolutionary scenario is also provided. Since issues regarding deploying AHS in the real world actually dictate AHS technological requirements, deployment research should be an integral part of AHS concept definition/evaluation and system design.