Preliminary AMS of the test corridor suggests the benefits of ICM strategies are greatest under the worst traffic conditions due to heavy demand and/or incidents. In the test corridor AMS, 1 to 4 percent of travelers shifted to transit in the presence of a major incident. Importantly, the test corridor AMS validated the hypothesis that implementation of ICM is not “one size fits all;” effective real-time corridor management requires selective implementation of different ICM strategies, depending on the extent of underlying nonrecurrent congestion (due to incidents, weather and other unexpected events) and on the severity of prevailing travel demand. Dynamically applying ICM strategies in combination across a corridor was shown to reduce congestion and improve the overall productivity of the transportation system.
Figures 5 and 6 present summaries of monetized annual benefits for the ICM strategies modeled in the AMS test corridor effort, using test corridor data, for the major incident operational conditions. The ICM strategies modeled, both individually and in combination, include highway traveler information, transit traveler information, local adaptive ramp metering, HOT lanes and arterial traffic signal coordination. Monetized benefits are combinations of five performance measures, including travel time, reliability of travel time, safety, emissions and fuel consumption.
Information regarding findings on specific ICM strategies can be found in the test corridor summary report titled, “Integrated Corridor Management Analysis, Modeling, and Simulation Results for the Test Corridor.” This report, and other useful resources, are available on the ICM Knowledgebase (www.its.dot.goc/icms/knowledgebase.htm).
Conclusions and Next Steps
Preliminary results of the AMS methodology applied to the test corridor demonstrated the following:
The test corridor modeling validated the ICM concept: Dynamically applying ICM strategies in combination across a corridor is shown to reduce congestion and improve the overall productivity of the transportation system.
The AMS methodology is able to analyze the individual and combination effects of ICM strategies under different operational conditions.
New analysis capabilities were successfully tested and produced intuitive results. These new capabilities include the analysis of: a) mode shift to transit, b) impacts of congestion pricing and c) impacts of traveler information.
The ICM AMS methodology offers the following benefits to corridor managers across the country:
Invest in the right strategies. The methodology offers corridor managers a predictive forecasting capability that they lack today to help determine which combinations of ICM strategies are likely to be most effective under different conditions.
Invest with confidence. AMS allows corridor managers to “see around the corner” and discover optimum combinations of strategies as well as conflicts or unintended consequences inherent in certain combinations of strategies that would otherwise be unknowable before implementation.
Improve the effectiveness/success of implementation. With AMS, corridor managers can understand in advance what questions to ask about their system and potential combinations of strategies to make any implementation more successful.
AMS provides a long-term capability to corridor managers to continually improve implementation of ICM strategies based on experience.
Starting in fall 2008, the USDOT will be working with the three selected pioneer sites (Dallas, Minneapolis and San Diego) to model and analyze the proposed ICM strategies documented in their ICM concepts of operation (the pioneer sites’ ICM concepts of operation documents are available through the ICM Knowledgebase at http://www.its.dot.gov/icms/knowledgebase.htm). The analysis will follow the approach defined in this article and will be tailored to the models, data and strategies available and to be implemented in each corridor. The analysis should be completed by summer 2009.
Vassili Alexiadis is a vice president with Cambridge Systematics Inc., and the principal investigator for the “ICM – Tools, Strategies and Deployment Support” project. Alexiadis is directing the analysis of ICM systems proposed by the stage 2 pioneer AMS sites, and the evaluation of expected benefits to be derived from implementing those ICM systems.
Brian Cronin serves as the RITA ITS joint program office manager for the ICM program. He is the Congestion Program coordinator for the ITS JPO and serves as technical representative for the Montgomery County, Md., and San Antonio, Texas, pioneer sites.
Steve Mortensen is a senior ITS engineer with the FTA Office of Research, Demonstration and Innovation. Mortensen is the technical representative for the Dallas, Texas, Oakland, Calif., and San Diego, Calif., pioneer sites.
Dale Thompson is a transportation research specialist in the Federal Highway Administration’s (FHWA) Office of Operations. He is also the technical representative for the Houston, Texas, Minneapolis, Minn., and Seattle, Wash., pioneer sites.
More Related Information:
Archived Article: Managing Congestion with Integrated Corridor Management