摘要: |
Traffic congestion, recurrent and non-recurrent, creates significant economic losses and environmental impacts. Integrated Corridor Management (ICM) is a U.S.DOT research initiative that has been proven to effectively relieve recurrent congestion and reduce non-recurrent congestion in a transportation network. Traffic signal coordination is an effective approach to improve travel speed and to decrease delays resulting in better travel times. Incorporating traffic signal coordination into ICM can further improve the benefits of ICM strategies. In this project, we propose an ICM optimization system. The optimization approach and the expert system are major components for the ICM optimization system. With respect to the expert system, it serves as a decision support system and a backup system for the optimization approach. For the optimization approach, an ICM optimization model is presented first. The effectiveness of the ICM optimization model is verified by a case study. To maximize the support of implementing ICM strategies from local transportation agencies and residents, we propose a real time and proactive offset tuning algorithm to reduce delays of detour traffic without disrupting the existing traffic. The presented algorithm explicitly incorporates diverted traffic and the diversion traffic patterns into existing traffic. The offsets of each coordinated intersection are fine-tuned and updated every ten cycles to provide smooth traffic progression for upcoming traffic within the next ten cycles. Case studies were conducted to prove the effectiveness of the proposed algorithm. The benchmark cases were established as the TRANSYT-7F coordination traffic signal timing plans. Based on the results, the proactive real time offset tuning algorithm can outperform TRANSYT-7F when the accurate diversion rates are not known in advance which conforms to reality. While, when the diversion rates are predetermined and the average additional diversion volume is taken into consideration for optimization by TRANSYT-7F, the proposed algorithm significantly reduces the number of stops and has comparable performances with TRANSYT-7F. The benefits and costs of implementing the proposed algorithm are analyzed. The net benefit and benefit to cost ratio over 10 years are nearly $2.5 million and 1.6, respectively, which shows that the proposed algorithm is worth for application. The upcoming ICM simulation test bed, ETFOMM, is introduced. It has two major advantages which are that it has convenient ICM built-in functions and its computation time is low which makes it have the ability to become an online decision support system for ICM strategies. In the last section, conclusions and recommendations of this study are presented |