GIS and Transportation Planning
Every day, millions of people around the world rely upon transportation to get them to where they need to go. Whether by car, train, or bus, most humans require these forms of mobility to survive. Geographic Information Systems (GIS) allows professionals who plan transportation systems and transportation system alternatives (TSAs) to spatially analyze the current and future affects transportation has on our environment, our infrastructure, and our economy.
What is Transportation Planning?
According to Wikipedia:
"Transportation planning historically has followed the Rational Planning model of Defining Goals and Objectives, Identifying Problems, Generating Alternatives, Evaluating Alternatives, and Developing the Plan. Other models for planning include Rational actor, Satisficing, Incremental planning, Organizational process, and Political bargaining. However, planners are increasingly expected to adopt a multi-disciplinary approach, especially due to the rising importance of environmentalism. For example, the use of behavioral psychology to persuade drivers to abandon their automobiles and use public transport instead. The role of the transport planner is shifting from technical analysis to promoting sustainability through integrated transport policies.[1]"
Source: http://en.wikipedia.org/wiki/Transportation_planning
The Use of Geographic Information Systems in Transportation Planning
Transportation planners use GIS in a multitude of ways, but the most common use is in transportation modeling. Transportation modelers collect transportation-related data (such as traffic volumes, speeds, lane types, turn limitations, directionals, and traffic flow capacities), as well as socio-economic data (such as household sizes and income levels), and input this data into a computer program that runs a series of calculations based upon certain parameters (such as time of day, speed limits, signal timing, etc.). The output is then processed and typically analyzed in tabular format. To better understand the patterns associated with traffic and other transportation-related variables, and to better serve the general public, transportation planners will take this data, and import it into a geographic information system. An example of such use is from the State of Florida, where the Florida Dept. of Transportation (FDOT) has developed a GIS application that integrates their existing model (Florida Standard Urban Transportation Model Structure (FSUTM) to a GIS. The application is called GIS-TM (Geographic Information System for Transportation Modeling. A software application called TransCAD is an excellent up-to-date integration of modeling and GIS capabilities.