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Title: An evaluation of a highway intersection gap acceptance metering system
Author: El-Hanna, F. I. H.
ISNI:       0000 0001 3442 8513
Awarding Body: University of Bradford
Current Institution: University of Bradford
Date of Award: 1974
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This thesis involves the description and the mathematical modelling of the operation of a motorway entrance ramp merging control system in order to provide a smooth interaction between merging and shoulder lane vehicles and to prevent congestion on the motorway. Headways, defined as the time spacing between two successive vehicles with respect to a stationary observer, are measured by loop detectors upstream of an entrance ramp. When an acceptable headway is detected, a ramp vehicle is released from a stationary position at a control signal so that it reaches the nose of the ramp at the same instant as the shoulder lane gap. The gap acceptance mode of control was studied and compared to an Uncontrolled condition. This was accomplished by developing two models describing a section of a motorway with an entrance ramp under control and under no control. Criteria for comparison included a number of figures of merit such as (1) Number of vehicles merging with the motorway stream without delay, (2) The average delay suffered by ramp vehicles along the acceleration lane; and (3) The average speed of the motorway vehicles at the end of the motorway section. On these criteria, gap acceptance control was more effective than the uncontrolled condition. Data were collected to evaluate ramp and motorway operating characteristics under the uncontrolled condition. Junction 17 the M62/A56 Flyunder was utilized as a study site. The method of observation used was time-lapse cinephotography. Four films of 30 minutes duration each were taken. From the films lag acceptance, and headway data were obtained. Lag acceptance data was separated into three groups depending on the speed of the merging vehicles. The shifted negative exponential distribution was found to be the best descriptor of motorway and ramp headways. A Marconi Radar Speedmeter Type S350 was used to measure spot speeds on the motorway and the entrance ramp. Dimensions of light and heavy weight vehicles were also measured at two service stations on the M62.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available