Distance Requirements for Ramp Metering

Distance Requirements for Ramp Metering
Author: Sameer Sharma
Publisher:
Total Pages: 42
Release: 1994
Genre: Electronic traffic controls
ISBN:

Freeway ramp metering systems are being used to alleviate urban freeway congestion. This report presents a methodology for determining the distance requirements for ramp metering for a wide range of traffic volume and freeway geometric conditions. The distance requirement for ramp metering consists of distance required queue storage and distance required for the freeway merging operation. A queue storage model has been developed to determine distance required for queue storage. The constant acceleration models of linear motion have been used to determine distance required for the freeway merging operation. A methodology for determining the optimal placement of the ramp meter signal has been presented. Guidelines for effecting a trade-off between queue storage an freeway merging distance requirements have also been presented. A sample problem demonstrates the use of the presented methodology.

Guidelines for Ramp and Interchange Spacing

Guidelines for Ramp and Interchange Spacing
Author: Brian Ray (Engineer)
Publisher: Transportation Research Board
Total Pages: 194
Release: 2011
Genre: Technology & Engineering
ISBN: 0309155487

TRB's National Cooperative Highway Research Program (NCHRP) Report 687: Guidelines for Ramp and Interchange Spacing explores guidelines for ramp and interchange spacing based on design, operations, safety, and signing considerations. The report is designed to help aid the decision-making process when an agency is considering new ramps or interchanges on existing facilities, modifying ramps and interchanges of existing facilities, or when planning and designing new highway and interchange facilities. The guidelines also offer standardized definitions measuring ramp and interchange spacing, which have varied in previous design guides. A final report documenting the full research effort related to the development of NCHRP Report 687 was published as NCHRP Web-Only Document 169--

Traffic Engineering Handbook

Traffic Engineering Handbook
Author: James L. Pline
Publisher: Prentice Hall
Total Pages: 504
Release: 1992
Genre: Technology & Engineering
ISBN:

A reference work offering information on the basic principles and the proven techniques of traffic engineering.

Ramp Metering Algorithms and Approaches for Texas

Ramp Metering Algorithms and Approaches for Texas
Author:
Publisher:
Total Pages: 96
Release: 2004
Genre: Algorithms
ISBN:

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.

Procedures to Determine Frontage Road Level of Service and Ramp Spacing

Procedures to Determine Frontage Road Level of Service and Ramp Spacing
Author: Kay Fitzpatrick
Publisher:
Total Pages: 154
Release: 1996
Genre: Frontage roads
ISBN:

The main objectives of this study were to develop procedures for estimating the level of service on freeway frontage roads and to determine desirable spacings for ramp junctions. The tasks involved developing (1) procedures for analyzing frontage road weaving sections, (2) recommended spacing requirements for ramp junctions, and (3) a technique to evaluate overall operations on a continuous frontage road section. The two weaving segments analyzed included a one-sided weaving area formed by an exit ramp followed by an entrance ramp and connected by an auxiliary lane and a two-sided weaving area formed by an exit ramp followed by a downstream signalized intersection.