Abstract:
The Indiana Department of Transportation (INDOT) maintains a TransCAD (registered trademark)-based statewide travel demand model (TDM) as one source of traffic forecasting and a history count database that contains all historical traffic counts for state highways as the other. The Traffic Forecasting Tool (TFT) was developed to incorporate forecasts from both sources. This incorporation helps the user of the tool to obtain alternative forecasts on a highway link and to investigate the validity of the forecasts. TFT is a TransCAD (registered trademark)-based geographic information system application that enables the user to access the link information stored in two sources simultaneously and to obtain alternative traffic forecasts based on two sources interactively. TFT performs two-tiered analyses in order to generate future forecasts. At the first tier, TFT estimates trendline equations for a selected highway link based on the link's traffic growth patterns. At the second tier, the link is evaluated by generating future forecasts for the user-specified analysis period. For estimation and evaluation, four forecasting models are incorporated in this tool: a linear straight-line fit model, a linear regression model, an exponential model and a modified exponential model. This paper presents the overall features of TFT, including forecasting algorithms and TFT user interfaces. Later, this paper also discusses the potential for further development of this tool.
