Open AccessDevelopment and Implementation of a 2-Phase Calibration Method for Gravity Model Considering Accessibility
Author(s) -
Sung Taek Choi,
Jeong Hyun Rho
Publication year - 2015
Publication title -
daehan gyotong hakoeji/daehan gyotong haghoeji
Language(s) - English
Resource type - Journals
eISSN - 2234-4217
pISSN - 1229-1366
DOI - 10.7470/jkst.2015.33.4.393
Subject(s) - deterrence (psychology) , calibration , norm (philosophy) , gravity model of trade , computer science , variable (mathematics) , function (biology) , econometrics , trip distribution , mathematical optimization , operations research , mathematics , statistics , economics , mathematical analysis , law and economics , evolutionary biology , political science , international trade , law , biology
??? ???? ? ? ??? ???? ??? ?? ???? ?? ??. ?? ??? ?? ??? ??? ??? ? ? ??? ?? ?? ??? ?? ????. ??? ?? ??? ???? ???? ??? ??? ??? ??? ??. ? ??? ??? ???? ??? ??? . ?? ?? ??? ??? ?? 2?? . ?? ??? ?? ?? ??? ?, ?? ???? ????. RMSE, E-norm, C.R? ??? ???? ??? ?? ??, ??? ?? ??? ??? ?? . ??, ??? ??? ??? ???? ?? ?? ??? ???? ?? ??? ? ??. ? ??? ??? ???? ??? ??? ??? ??? ?? ? ? ??? ??? ?? ???? . Gravity model has had the major problem that the model explains the characteristics of travel behavior with only deterrence factors such as travel time or cost. In modern society, travel behavior can be affected not only deterrence factors but also zonal characteristics or transportation service. Therefore, those features have to be considered to estimate the future travel demand accurately. In this regard, there are two primary aims of this study: 1. to identify the characteristics of inter-zonal travel, 2. to develop the new type of calibration method. By employing accessibility variable which can explain the manifold pattern of trip, we define the zonal travel behavior newly. Furthermore, we suggest 2-phase calibration method, since existing calibration method cannot find the optimum solution when organizing the deterrence function with the new variables. The new method proceeds with 2 steps; step 1.estimating deterrence parameter, step 2. finding balancing factors. The validation results with RMSE, E-norm, C.R show that this study model explains the inter-zonal travel pattern adequately and estimate the O/D pairs precisely than existing gravity model. Especially, the problem with estimation of short distance trip is overcomed. In conclusion, it is possible to draw the conclusion that this study suggests the possibility of improvement for trip distribution model