Travel Demand Model Development For Small Urban Areas

The primary purpose of a corridor or route study is to assess a number of proposed options and identify a preferred solution to address existing and future deficiencies in a corridor. The assessment process typically includes an analysis and evaluation of the character and extent of congestion and mobility problems within the corridor. Travel demand models play a key role during the evaluation process; current planning practice relies on the ability of urban travel demand models to provide the transportation data used as evaluation measures in comparing and assessing the benefits provided by each option or alternative. Unfortunately, when conducting corridor studies in rural or small urban areas with less than 50,000 population a travel demand model may not exist to assist study requirements. Recently, a comprehensive corridor study of US 59 was conducted aimed at determining both short term and long term needs for the facility. Included within the longer term needs and vision for the corridor is the operation and interaction of US 59 with two separate small urban area loop highways and the potential for US 59 to be designated an interstate facility (I-69). The limits of the corridor study encompass two counties (Angelina and Nacogdoches) and the cities of Lufkin and Nacogdoches. An added dimension to the study is the recognition that both Angelina and Nacogdoches Counties have been experiencing rapid population growth (two percent per year) and may ultimately be designated a metropolitan statistical area (MSA). With this in mind it was determined at the onset of the study that an appropriate and beneficial technical approach would involve Major Investment Study (MIS) guidelines. Having structured an approach based upon MIS guidelines, the project subsequently required the development of a travel demand model for the two county region since one did not already exist. In addition, the project schedule required that a model be developed and implemented within a short timeframe. This paper will examine the expeditious development of a travel demand model for a small urban area using transferable travel parameters and existing travel survey data. The paper will review the perceived needs in deciding that a model needed to be developed and summarize model validation results. Additionally, it will describe the integral role the model played in evaluating alternatives and ultimately choosing a preferred alternative. The paper will provide useful information to agencies and small urban areas that do not currently have models and desiring to quickly implement a travel demand model as part of their methodological process.