Many transportation professionals have dedicated time, effort, and money towards the development of manuals for evaluating the mobility and safety of transportation systems. At this time, the profession has published five editions of the Highway Capacity Manual (HCM) and one edition of the Highway Safety Manual (HSM). A purpose of these manuals is to aid transportation professionals in making decisions in a consistent manner. Additionally, the Federal Highway Administration (FHWA) and transportation profession continues to update and publish the Manual on Uniform Traffic Control Devices (MUTCD) through federal rule making. However, it is beyond the MUTCD's scope to provide the breadth of knowledge necessary for evaluating traffic control devices (TCDs) as part of the larger transportation system. In this dissertation, the author uses existing theory and a survey of transportation professionals to develop a decision support tool for use in selecting TCDs in a consistent manner. To accomplish the research objectives, the author first uses a survey of transportation professionals to evaluate the relative importance of safety, mobility, environmental sustainability, and economic activity when an agency selects TCDs. The author finds that safety and mobility are the engineering benefits driving the selection of TCDs. Additionally, the author concludes that the best solution meets local needs and desires, conforms to engineering principles and practice, and provides an engineering benefit. Next, the author uses a portion of the same survey of transportation professionals to evaluate the importance of crashes, driver compliance, and mobility when ranking of transportation alternatives. The author concludes that compliance is a reasonable surrogate measure of safety in the absence of crash data. From this investigation and existing theory, the author proposes performance for use in the developed decision support tool. In the third step, the author uses the importance of agency objectives evaluation and the identified performance measures to develop a decision support tool for use in selecting TCDs. The author demonstrates the use of the nine-step decision support tool using a case study that evaluates the use of an all-way stop versus a two-way stop, versus a marked crosswalk.
