Simulating traffic for incident management and ITS investment decisions

UTPS-type models were designed to adequately support planning activities typical of the 1960's and 1970's. However, these packages were not designed to model intelligent transportation systems (ITS) and support incident management planning. To overcome these limitations, improved algorithms have been proposed and tested in some markets. Unfortunately, these improvements generally have not been included in the commercially available packages and agencies continue to use UTPS-type packages. Therefore, our effort is intended to supplement existing planning model capabilities by exploiting the capabilities of available micro-simulation models. Micro-simulation models can assess , for a localized area or corridor, the effect of ITS implementation and incident response. We introduce a modeling methodology where a sketch-level model represents the regional network and we retain a portion of the available links to develop roadway detail in the area proxi-mate the proposed ITS technology deployment or incident. The combined system is designed to provide real-time travel information for agencies to improve traffic flow through changeable message signs or advanced traffic signals and for travelers to alter route or destination choices through pre-trip information systems such as cable television or web sites. Within this paper, a methodology is demonstrated that uses a GIS interface between Tranplan and Corsim for a test case in Des Moines, Iowa, a medium sized urban area. INTRODUCTION Conventional transportation planning developed in the early six-ties when cities with populations exceeding 50,000 were required to develop " continuous, comprehensive, and cooperative " plans to support the development of the Interstate Defense Highway System through region-wide, systems-oreiented studies with long horizon times (1). In the 1970's, transportation planning shifted towards shorter horizon years focusing on corridor analysis. The eighties continued the focus on shorter horizon transportation planning and saw continued improvements in computer tools and computing capabilities. The 1990's have seen a division in planning horizons with shorter horizons focusing on transportation system management, and longer planning horizons focusing on sustainablility. Funding provided by in the Intermodal Surface Transportation Efficiency Act of 1991 promoted the development of intelligent transportation systems (ITS) to improve traffic flow and incident management response (2). However, planning and engineering agencies continue to forecast travel using the sequential modeling methodology developed in the 1960's, which was not developed to and have limited ability to address ITS planning issues. Although work is being performed by the Travel Model Improvement Program (TMIP) to improve traffic models for incident management and ITS investment …