Transport Planning - HKU Libraries - The University of Hong Kong

T.P.D.M.V.U(Al/2001)1.4.5 Development of Transport Model1.4.5.1 A transport model is often required as a study tool to provide traffic forecasts for the futuredesign years. A suitable model needs to be developed or updated to suit the specificrequirements of each individual study.1.4.5.2 As a prerequisite in developing a transport model, it is necessary to define the zoning systemand the transport networks first. The process is briefly described in the followingparagraphs.Zoning System1.4.5.3 An early step in any transport planning study is to define the area which is to be studied indetail. This could be the whole Territory in the case of a territorial transport planning study,or one of its sub-regions or districts in the case of a sub-regional or district traffic study. Thestudy area will have to be divided into small units referred to as traffic zones. This is doneso that the origins and destinations of travel can be closely defined geographically and thefactors associated with trip making such as population and employment can be spatiallyquantified and collated as input to a transport model.1.4.5.4 The size and, therefore, the number of zones required are related to the type of study, viz.territorial, sub-regional and local area. In general, the size should not be so small that therelevant data collected are statistically unreliable, or so large that all differing data areaggregated making a useful analysis of the traffic implications not possible. Anunnecessarily large zone would also create concentrated traffic loading at particular spots ofthe network, thereby distorting the overall situation.1.4.5.5 The delineation of zone boundaries should take the following consideration into account-(i)(ii)(iii)(iv)Compatibility with census enumeration units (i.e. Tertiary Planning Unit and StreetBlock) so as to permit the use of census data;Homogeneity of activities, or alternatively predominance of one land-use;Anticipation of changes in land-use or transport network; andAccessibility of road and public transport.In respect of the last factor, the zoning system should reflect in particular the catchment areaof rail service. For rail stations, this is normally defined as the development within a rangeof 500m to 1km. This is a guideline only. The zoning system should also be capable ofindicating the use of major roads and, therefore, zones should not span several major roads.1.4.5.6 A system of 329 traffic zones was developed for use in the CTS-3 model, which has beenexpanded to a PVS 1 338-zone system. The 338 traffic zones are shown in Diagrams 1.4.5.1,1.4.5.2 and 1.4.5.3 for Hong Kong Island, Kowloon (including Tsuen Wan) and the wholeTerritory respectively.1 PVS - Planning Vision and Strategy