تخمين ماتريس مبدا - مقصد با استفاده از اطلاعات حجم ترافيك كمان هاي شمارش شده

چكيده انگليسي :

78 Estimation of Origin Destination Matrix Using Links Traffic Counts Mohammed Pooyanmehr m pooyanmehr@cv iut ac ir Date of Submission Department of Civil Engineering Isfahan University of technology Isfahan Iran Degree M Sc Language FarsiSupervisor Sir Nader Shetab shetab@cc iut ac irAbstractProcess of forecasting trips is one of the most applicable sectors of transportation planning According toefficient information and accurate analysis such processes can be used as an efficient attribute during futuredevelopments Data required to forecast trips is stored in a matrix called Origin Destination matrix In fact this matrix consists of the origin destination data of the transportation network which can be obtained via twodirect and indirect methods Direct methods to construct origin destination matrix obtain the data directlyfrom origin of the trip destination of the trip and during of the trip by asking questions from passengers orobserving trips being made Since construction of the origin destination matrix using direct methods is somuch costly and time consuming hence implementation of such methods is not reasonable Indirect methodstry to estimate origin destination matrix for the current year on the basis of existing matrices of some yearsbefore using existing traffic volume of some network links and mathematical methods These methods aremostly in the form of mathematical programming problems Since s up to now indirect methods have beenenormously developed In this research estimation methods of Origin destination matrices were consideredby counting traffic of some of the links Then one of the most applicable methods called Spiess s gradientwas chosen from the set of methods being considered Also in this research a model is proposed to estimate demand matrix by counting traffic of some of the links This model incorporates the idea of partial allocation Partial allocation method allocates origin destinationmatrix to the transportation network while the presented estimation technique of this research operates in areverse manner In the presented technique a matrix is estimated in each stage in order to reproduce thevolume of the counted links gradually Since number of unknowns number of elements of the origin destination matrix are more than knowns number of counted links then one can find lots of matricescapable to reproduce volume of the counted links when being allocated to the network Also there exists anold matrix for this network and such a matrix includes the total framework of the trips being made betweenorigin and destination Hence confinement of the estimated matrix to the old one can be a logicalassumption In the proposed method the estimated matrix can be confined to the old matrix by defining somegoals in such a way that a unique and reliable matrix can be achieved Also this method can utilize additionalinformation such as amount of trips being made and absorbed in each region Such information can help themodel to estimate the demand matrix much more accurately In order to analyze efficacy of the proposed method and Spiess s gradient method we have utilizedmathematical analysis and some samples have been considered for small and large networks Computationalresults demonstrate that when additional information exists for the considered network the presented methodcan definitely be more accurate and reliable In case of not having such additional information the estimatedmatrix resulted from the heuristic method does not differentiate from the matrix resulted from Spiess sgradient method Keywords origin destination matrix Mathematical Programming problem TransportationNetwork Heuristic Algorithm

پويان مهر، محمد

تخمين ماتريس مبدا - مقصد با استفاده از اطلاعات حجم ترافيك كمان هاي شمارش شده

مسئله برنامه ريزي رياضي , شبكه حمل و نقل , الگوريتم ابتكاري