Selection of measures of performance on calibrating parameters in car following models

To reveal the influence of selection of measures of performance (MOP) on the calibration of car following models, different performance indices were chosen and absolute error RMSE and relative error U coefficient were used as the objective functions to calibrate the parameters of 3 main car following models including Gipps, IDM and Newell models based on measured US I-80 highway traffic data. Then the reason of error formation was analyzed during calibration in both qualitative and quantitative methods. The results show that space headway performs better than velocity on the effect of calibrating car following models. Moreover, in the process of optimization, the displacement that follower travels in one interval is the basic variable; compared with velocity, space headway as MOP decreases the goodness-of-fit of the spatial displacement of follower that travels in one interval, but it is good at representing exact process of car following by real traffic data; therefore, the space headway has a better description capability to car following motion in general, and taking space headway as a performance index to calibrate the parameters of model is capable of improving the reliability and accuracy of car following models. © 2017, Editorial Department of China Journal of Highway and Transport. All right reserved.