Ramp Metering Algorithms and Approaches for Texas

Ramp Metering Algorithms and Approaches for Texas

Author:

Publisher:

Published: 2004

Total Pages: 96

ISBN-13:

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The primary objective of this project was to compare ramp metering algorithms and develop guidelines for improving ramp metering operations in Texas. As part of this research project, researchers collected data at several sites in Houston, Texas. Data analysis showed that many congested freeways are facing heavy ramp demand, and require significant changes in existing ramp metering operations if ramp metering continues to be used as part of freeway traffic management. Furthermore, researchers used computer simulation to compare the effectiveness of ALINEA with queue flush with the existing strategy of metering at the maximum rate with queue flushing. Researchers found that ALINEA does not provide any benefits when queue flushing is permitted. Under heavy demand conditions such as those in Houston, the current strategy to meter at the fastest rate remains the most beneficial. However, this strategy also provides limited benefits. Finally, researchers developed guidelines and recommendations for current and future ramp metering operations in Texas. This report documents the research results.


Preferential Lane Treatments for High-occupancy Vehicles

Preferential Lane Treatments for High-occupancy Vehicles

Author: Charles A. Fuhs

Publisher: Transportation Research Board

Published: 1993

Total Pages: 92

ISBN-13: 9780309053129

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This synthesis will be of interest to transportation planners, highway engineers, environmental personnel, highway design engineers, transit planners, highway administrators, and others concerned with the planning, design, and operational features of preferential high- occupancy vehicle (HOV) lanes on highways. Information is provided on the current and proposed state of the practice in North America. This synthesis describes the state of the art with respect to preferential treatment for HOVs on highways. This report of the Transportation Research Board provides information on long-distance facilities, such as barrier-separated, concurrent-flow (separated and nonseparated), and contraflow facilities, as well as on short-distance facilities, such as queue by-pass lanes. Planning, design, and operational features of each treatment are described. The issues and operating results are described, and specific case studies are included.