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Improving Roundabout Performance Using Roundabout Metering Technique

Mahmood, Kashif
http://rave.ohiolink.edu/etdc/view?acc_num=akron1463499775

Abstract Details

2016, Master of Science in Engineering, University of Akron, Civil Engineering.
Circular intersections have been part of our traffic in the United States for more than 100 years. They existed in the form of Traffic Circles and rotaries. Traffic circles were first used in order counter the traffic problems, which had begun as a result of an increase in traffic. In the beginning traffic circles were a huge success and had great benefits over traffic signals. It not only reduced the cost involved in signalization but also reduced the delay time to a great extent. In addition, it increased the capacity of the intersection. But as the traffic increased over the period of time, traffic circles began to see problems arise. The traffic circles gave priority to the high speeding vehicles entering the intersection. As a result rate of crashes increased significantly and thus the traffic circles were ruled out in the United States during the 1950s. The roundabouts were introduced in the 1960s in the United Kingdom. However, they were not introduced in the United States until in the 1990s. The roundabouts had a major difference from the traffic circles where the roundabouts gave priority to the circulating traffic instead of priority to the entering traffic like in the traffic circles. Also, speed in the intersection was reduced by the deflection inside the intersection resulting in great reduction in the crash rate while providing many other benefits like increased capacity, reduced delay time and no signalization costs. But with the ever increasing traffic, roundabouts too faced problems especially when the traffic was high during peak times. The during heavy traffic flow from one or more of the upstream approaches block one or more of the downstream approaches thus forcing high delay time and queues on that approach. As a result, roundabout metering was introduced with an intention of reducing delay and queues on the roundabout. The Roundabout metering meters the upstream approach when there is a queue detected on the downstream approach. It managed to give sufficient gaps to the traffic on the downstream approach so that the vehicles have time to enter the intersection, thus reducing the delay time and the queue length in that approach. However, roundabout metering is only applied part-time and restricted to one or two approaches and does not work when the there is an unpredictable flow. Hence, in this research, an adaptive metering method has been used. The adaptive metering method is applied to all approaches and at all time of the day. It takes care of any unpredictable flow. The two roundabouts the Tallmadge Circle, and the Goodyear roundabout, which have been experiencing very high delay and queues, were chosen for this research. Two adaptive methods with different timing strategies for two different situations have been developed. Both of these methods are combined to act as a single method to improve the performance of the roundabout. Models similar to the roundabouts were created in VISSIM microscopic simulation software. C++ coding is done for the method in VISSIM’s API (Application programming interface) using the Visual Studio. The simulation was run and the results from it showed improved delay time and queue length. In conclusion, adaptive metering is a great improvement over the roundabout metering and can be used in roundabouts which have unpredictable flows. However, more research is recommended with more roundabouts before being implemented.
Ping Yi (Committee Chair)
Craig Menzemer (Committee Member)
Patnaik Anil (Committee Member)
56 p.
Civil Engineering; Transportation

Recommended Citations

Citations

  • Mahmood, K. (2016). Improving Roundabout Performance Using Roundabout Metering Technique [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1463499775

    APA Style (7th edition)

  • Mahmood, Kashif. Improving Roundabout Performance Using Roundabout Metering Technique. 2016. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1463499775.

    MLA Style (8th edition)

  • Mahmood, Kashif. "Improving Roundabout Performance Using Roundabout Metering Technique." Master's thesis, University of Akron, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1463499775

    Chicago Manual of Style (17th edition)

akron1463499775
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© 2016, some rights reserved.Creative Commons License Improving Roundabout Performance Using Roundabout Metering Technique by Kashif Mahmood is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Akron and OhioLINK.