Research Projects Supported by HKU's High Performance Computing Facilities
 
Researcher:
Dr S C Wong, Department of Civil Engineering
Project Title:
A Multi-commodity Discrete/Continuous Approach to Traffic Equilibrium Problems
 
Project Description:

Consider a study area with several highly compact transportation facilities, and the travelers' origins for each of them are continuously dispersed over the whole study area. The transportation system is divided into two layers: major freeways and dense surface streets. Whereas the major freeway network is modeled in the conventional discrete network approach, the dense surface streets are approximated as a continuum. The travelers to a particular facility will either travel in the continuum (surface streets), exchange to the discrete network (freeways) at an interchange point (ramps), and then move to the facility on the discrete network; or travel directly to the facility in the continuum. Specific cost-flow relationships on the two layers of transportation facilities are considered. The objective of the research is to develop a traffic equilibrium model for the above multi-commodity discrete/continuous transportation system, in which for a particular origin-destination pair no travelers can reduce their individual travel costs by unilaterally changing route. This approach provides a more realistic model for the transportation system, in which the travel demand is continuously distributed over the city rather than concentrated at some arbitrarily chosen point sources (centroids) and most travelers tend to find a nearby interchange to move to the discrete freeway network to take advantage of high speed movements, except those who are close to the facility.

 
Project Duration:
1 December 2000 - 30 November 2003
 
Project Significance:

This research provides an enhanced modeling framework for traffic assignment problems by combining the discrete and continuous network equilibrium modeling approaches. Applications of such methodology include planning and assessment of park and ride facilities and transit stations (if the discrete freeway network is replaced by a transit network), feasibility study of build-operate-transfer (BOT) projects, and evaluation of catchment areas for major transportation facilities. This discrete/continuous modeling approach provides a more realistic representation of travelers' movements in a transportation system, taking into consideration of the spatial distribution of demand and its interaction with freeways and surface streets.

 
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Results Achieved:
Wong S.C. and Wong G.C.K. (2002) An analytical shock-fitting algorithm for LWR kinematic wave model embedded with linear speed-density relationship. Transportation Research, 36B, 683-706.

Wong G.C.K. and Wong S.C. (2001) A multi-class traffic flow model ?an extension of LWR model with heterogeneous drivers. Transportation Research, 36A, 827-841.

Wong S.C., Zhou C.W., Lo H.K. and Yang H. (2002) An improved solution algorithm for the multi-commodity continuous distribution and assignment model. ASCE Journal of Urban Planning and Development, in press.

Wong S.C., Du Y.C., Ho H.W. and Sun L.J. (2002) A simultaneous optimization formulation of a discrete/continuous transportation system. Transportation Research Record, in press.

Ho H.W., Wong S.C. and Loo B.P.Y. (2003) A continuous traffic equilibrium model with multiple user classes. Journal of the Eastern Asia Society for Transportation Studies, 5, 2831-2845.

卢佩莹, 黄仕进, 何鸿威 (2003) 香港及珠江三角地区内的机场竞争. In 陈广汉, 周运源, 叶嘉安, 薜凤旋 (eds.), 提升大珠江三角洲国际竞争力研究, 广州: 中山大学出版社, pp 293-323.

 
Remarks on the Use of High Performance Computing Cluster:

The HPC Cluster provides a high-power computing platform, which is essential for conducting basic and application research that are computational demanding.

 
Email Address:
hhecwsc@hkucc.hku.hk

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