Well designed signs and symbols provide supplemental information to properly guide motorists to attractions and improve nearby traffic flow and safety. Major Traffic Generators (MTGs) are important regional attractions, events, or facilities, which attract individuals or groups from beyond a local community, city, or metropolitan areas, and require even more proper guide signing due to the large amount of attendance. Concise and legible symbols and/or signs, if properly designed and placed, should be helpful in alleviating traffic impacts by MTGs to surrounding roadway networks. Therefore it is necessary to establish the eligible criteria and warrants for MTG guide signs. Possible MTG criteria include community population, site generated traffic, parking space, proximity to major corridors, etc., which are normally based on engineers’ experiences and opinions, and thus are hard to be quantified and formulated. In this book, the fuzzy logic based methodology is proposed to synthesize the eligible MTG criteria for MTGs through algorithms based on the summary of existing manuals in some states in U.S., and on expert knowledge from a survey to engineers in traffic operations.