Developing a simulation model to evaluate the capacity of weaving sections
Al-Jameel, HAE 2011, Developing a simulation model to evaluate the capacity of weaving sections , PhD thesis, Salford : University of Salford.
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Weaving sections have proved to cause bottlenecks on motorways because of the relatively frequent lane changes in these sections. The use of analytical models in assessing weaving section capacity (such as those suggested by the Highway Capacity Manual-HCM) has proved to produce some inaccurate results. This could be due to the more complex nature of this section compared with an isolated merging or diverging ones. In this study, a new weaving micro-simulation model has been developed to focus on the behaviour of drivers along a weaving section. This model consists mainly of four essential algorithms to represent car-following, lane changing, gap acceptance and weaving rules. The model was developed with data on drivers' characteristics at weaving sections which was used in its calibration and validation processes. A large amount of data from loop detectors obtained from the Highways Agency (i.e. the Motorway Incident Detection and Automated Signalling-MIDAS) was collected. However, such data alone was found to be inadequate for studying weaving section characteristics. Therefore, over 50 hours of video recordings were collected from several weaving sections within the Greater Manchester Area. Such comprehensive resource of field data helped in investigating other characterises such as effective length, the percentage of segregation vehicles and merging/diverging points. The results suggest that the effective length could be considered as about 200m for ramp weaving sections where the actual weaving length is greater or equal to 300m. whereas this effective length represents the whole weaving length when the actual weaving length is less than 300m. In addition, the majority of drivers performed their merging as early as the first 100m from the entrance point. Similarly, high proportions of diverging drivers entered the auxiliary lane very close to the entrance point. The newly developed model was applied in testing the effect on capacity of having different percentages of heavy goods vehicles and a range of volume ratios. New management scenarios were also applied using the developed model such as changing the configuration type of weaving sections from Type A to Type B and shifting the point of diverging (i.e. moving to the auxiliary lane) further downstream of the entrance point for a certain specified distance. The results suggested an improved operational performance in terms of reducing the
|Item Type:||Thesis (PhD)|
|Schools:||Colleges and Schools > College of Science & Technology|
Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering
|Depositing User:||Institutional Repository|
|Date Deposited:||03 Oct 2012 14:34|
|Last Modified:||18 Feb 2014 11:10|
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