INVESTIGATION OF THE EFFECTS OF LIMITED
RAMP CLOSURES ALONG THE H-1 FREEWAY


PI: Panos D. Prevedouros, Associate Professor of Civil Engineering
Assistants: Yuhao Wang (MSCE), Honglong Li (PhD), and BSCE students Lani Andam, Brian Babb, A.K. Colburn, George Lau, Lizi Olson, Jennifer Arinaga.

Sponsor: Highways Division, Hawaii DOT (20%) and Federal Highway Administration (80%) - HDOT Project Manager: Douglas Meller

Project Duration: November 1996 - December 2002

The objective of the project is to identify potential ramps on the most central segment of the H-1 freeway between Koko Head Ave. and Middle St. which, if closed would cause a significant improvement of the flow conditions on the freeway without causing major congestion on adjacent City streets. Freeway and network simulation by computer is used to 1) assess existing conditions, 2) identify ramps whose closure will yield major benefits to the freeway flow, and 3) select ramps whose closure will be both beneficial to freeway flow and not significantly detrimental to flow conditions on City streets.

As part of this project, a number of surveillance flights were made using the Honolulu Fire Department helicopter in fall 1996. Images from this survey are available through the highlighted link above.

Prior experience with ramp closure analysis indicates that considerable mainline speed increases should be expected after the closure of ramps that cause excessive impedance to the mainline flow. Because of the high likelihood that ramp closure is beneficial, the project also includes the design of an experiment for a ramp closure.

TSIS-CORSIM, KRONOS, Integration and TRANSYT-7F were used extensively in the analysis of freeway and mixed freeway/arterial networks. Several portions of the simulations, model tests and results of this project have been published in Transportation Research Record, ITE Journal and TRB Conference Proceedings.

Analysis of actual freeway data collected with video cameras and analyzed with AUTOSCOPE was conducted to gauge the proximity of freeway simulation results to reality (e.g., actual versus simulated speeds for a given level of flow at a given location). Also the accuracy of AUTOSCOPE, pneumatic counters and inductive loop detectors for volume data collection are being assessed.

A full-scale 2-week experiment of a ramp closure was conducted in the Fall of 1997. Extensive data collection on all ramps and many streets, as well as video recordings of freeway flow at 5 locations, helicopter video surveillance and post-closure motorist questionnaire surveys were used for impact assessment and evaluation.

A total of three technical reports were published from this project. Extended executive summaries from each report are available by clicking each of the links below.

Volume 1: PROJECT DESCRIPTION & WEST BOUND ANALYSIS

Volume 2: EAST BOUND H-1 FREEWAY ANALYSES AND RECOMMENDATIONS

Volume 3: WEST BOUND LUNALILO STREET ON-RAMP CLOSURE: JUSTIFICATION, DESIGN AND ANALYSIS OF RESEARCH EXPERIMENT.



Last updated on May 5, 2003.