Identifying and Prototyping Integrated Corridor Management (ICM) Strategies for Application in Virginia
Sampson K. Asare
Brian L. Smith, Ph.D., P.E.
Highway congestion is a major problem in urban transportation, and the search for feasible mitigation measures continues to evolve with advancement in technology and better understanding of traveler behavior. Due to institutional barriers and traditional practices, individual subsystems within a “corridor”—for example, arterial signal control systems and transit systems—have been operated independently, in isolation from each other. This management approach often leads to improving the performance of one subsystem at the expense of others. A more efficient approach that has the potential to improve corridorwide mobility is to coordinate the management of the individual transportation subsystems in order to make them operate collaboratively. This holistic approach is referred to as integrated corridor management (ICM).
In order to explore and demonstrate the potential for ICM application in Virginia, an investigation into the factors that are critical to its successful implementation and operation was conducted. Critical success factors were identified from the eight ICM “pioneer” sites sponsored by a U.S. Department of Transportation ICM initiative. The three most critical factors identified include (1) a robust Intelligent Transportation Systems (ITS) infrastructure; (2) the need for stakeholder partnerships and development of institutional frameworks within which ICM will be implemented and operated; and (3) the need to adopt standards and protocols through which information will be disseminated.
Additionally, the potential effectiveness of ICM as a congestion mitigation measure in Virginia was explored by prototyping the application of a set of ICM strategies in a simulation environment using a segment of the I-95/I-395 corridor (between mile marker 152 and mile marker 163) as a test bed. The strategies implemented include variable speed limits; ramp metering; transit signal priority; financial incentives (reduction in transit and parking fees); high occupancy toll (HOT)/high occupancy vehicle (HOV) lanes and HOV bypass; and increased transit and parking capacity. Analysis of the simulation results revealed that corridor person flow per hour had the potential to be increased by 14% under non-incident traffic conditions, compared to 38% during incident conditions. In terms of average travel time, the I-95 general purpose lanes could potentially experience a reduction of 48% and 58% under non-incident and incident traffic conditions, respectively. Whereas the average travel time on the HOV lanes remained essentially unchanged, average travel times on the primary arterial (U.S. 1N) improved by 29% under both non-incident and incident conditions. Additionally, the amount of fuel usage was reduced by 34% and 33% during non-incident and incident conditions, respectively. Although the cost of ICM implementation is high, benefit-cost ratios of 4:1 and 6:1were obtained for non-incident and incident conditions, respectively.
Based on the analysis results, it is recommended that variable speed limits, increased transit and parking capacities, HOV bypass lanes, and HOV/HOT lanes be considered the most promising for future ICM implementation in Virginia.
In order to achieve the study objectives, the project was divided into eight main tasks: 1. Literature review on ICM 2. Selection of site to test prototype ICM strategies 3. Identification of best practices and potential ICM strategies 4. Development of ICM evaluation methodology 5. Development and validation of simulation network 6. Evaluation of proposed ICM strategies 7. Analysis of results 8. Development of recommendations.
Selection of Test Site:
The Northern Virginia (NOVA) VDOT district initiated an ICM project in late 2011 along I-95/I-395, and a final concept of operations document is scheduled to be released later this year. The potential to coordinate this research with that of NOVA motivated the research team to change its initial choice of study areas (I-264/U.S. 58 corridor Virginia Beach and I-66 corridor in NOVA) and focus on the I-95/I-395 corridor instead.
Final Report as Published on VCTIR: