Analysis and Simulation Tools

Analysis tools support decisionmakers with credible information about how elements of the transportation system will operate under a variety of scenarios and conditions. These tools range from simple sketch-level methods to complex models. The choice of which tool to use depends upon the nature of the improvements under consideration. Regardless of the method chosen, the tool should provide objective assessments of transportation investments and performance. Applied appropriately, the tools facilitate more informed decisionmaking. The right tool will allow users to evaluate multiple scenarios and support efforts to mainstream the consideration of operations into planning practices.

A wide variety of tools has been developed and is available for use.

• Sketch planning tools
• Deterministic tools
• Travel demand forecasting models
• Simulation tools
• Archived operations data
• Operations-oriented performance measures/metrics
• Traffic signal optimization tools

More advanced analysis methods are being studied and integrated into modeling and analysis of operations including:

• Dynamic traffic assignment methods
• Multi-scenario methods
• Multi-resolution modeling
• Activity-based modeling

Dynamic traffic assignment (DTA) is defined in laymen terms as "a capability to describe how trip makers may take alternative routes when the roadway condition is different from normal condition." DTA is a type of modeling tool that combines network assignment models, used primarily in conjunction with travel demand forecasting procedures for planning applications, with traffic simulation models, used primarily for traffic operational studies. These tools support transportation network planning and traffic operations decisions, including evaluation of ITS deployment options, congestion pricing, and other operational strategies, through the use of simulation-based dynamic traffic assignment.[1]