Congestion impacts our daily lives, wasting fuel, lengthening trips and threatening business. The U.S. Department of Transportation (USDOT) launched the Integrated Corridor Management (ICM) initiative in 2005 to address these challenges by demonstrating how intelligent transportation systems (ITS) technologies can help transportation system operators and managers efficiently and proactively manage the movement of people and goods in major transportation corridors. The ICM initiative aims to pioneer innovative multimodal and multi-jurisdictional strategies that optimize existing infrastructure to help manage congestion in our nation’s transportation corridors.
In 2006, the USDOT selected eight pioneer sites to act as critical partners in the development, deployment and evaluation of ICM strategies. The pioneer sites include Oakland and San Diego, Calif.; Dallas, Houston and San Antonio, Texas; Montgomery County, Md.; Seattle, Wash.; and Minneapolis, Minn.
Using existing assets such as transit signal priority, ramp metering, real-time parking availability information systems, electronic payment and traveler information technologies, transportation corridor operators and managers can employ an array of ICM strategies to improve the movement of people and goods. With so many choices, agencies are interested in analyzing the potential benefits of the various approaches to help them decide on specific ICM strategies to implement.
The USDOT developed the ICM analysis, modeling and simulation (AMS) methodology to help transportation decision-makers identify the best ICM strategies for their needs under different conditions (such as planned special events, high traffic congestion or major incidents). The approach is unique in that it combines elements of existing models to support comprehensive assessment of ICM strategies not available today through any single tool. Once validated, the USDOT will make the approach available to transportation system managers and operators to help them implement ICM.
The USDOT took the first steps in spring 2008 toward validating the approach and generating initial insights into possible ICM benefits by applying the AMS methodology to a test corridor. Beginning in fall 2008, the USDOT will apply the AMS methodology to analyze the potential benefits of proposed ICM strategies at three of the eight ICM pioneer sites: Dallas, Texas; Minneapolis, Minn.; and San Diego, Calif. The application of AMS to the ICM strategies of these pioneer sites will yield insights that can help other transportation system managers and operators across the country select and apply optimum ICM strategies in their corridors. The USDOT will make the results from the test corridor AMS efforts available to transportation practitioners around the country on the ICM Web site through its knowledge and technology transfer activities.
The ICM AMS Approach
The AMS approach was designed to leverage the strengths of various analysis tools, such as travel demand models, mesoscopic simulation models and microscopic models. The approach was designed to address key gaps in current modeling approaches, including: a) the analysis of traveler responses to traveler information; b) the analysis of strategies related to tolling/high-occupancy toll ( HOT) lanes/ congestion pricing; and c) the analysis of mode shift and transit.
This modeling approach is based on the realization that different tool types have different advantages and limitations. There is no one tool type at this point in time that can successfully address the analysis capabilities required by ICM AMS requirements. No single model available today provides visibility into the cascading impacts of various congestion management strategies, much less combinations of strategies, across the entire network, transportation modes and facility types. The ICM AMS methodology can support corridor management planning, design and operations by integrating the three tool types and combining their capabilities.