Origin destination matrix estimation based on traffic counts using fmincon function in matlab

Abstract EN

Most methods of traffic planning study require origin-destination (OD) matrices, which describe the trip demands between the origin and destination nodes in the network.

this work is about the od matrix estimation problem, which means estimating od matrices from observed link flows.

this study aims to provide an easy-to-use and cost-effective alternative software that researchers and planners in developing countries can access without restriction.

the fmincon function in matlab software was used to create specialized code for estimating the od matrix in congested networks using three different optimization approaches at the upper level: generalized least square (GLS), ordinary least square (OLS), and maximum entropy (me) aggregated with user equilibrium assignment in the lower level.

to test the performance of the provided models, a corridor hypothetical network was created, and two cases of reliability factors were suggested, followed by a detailed statistical analysis.

the three proposed approaches produce adequate results, the improvement rate in error between observed and estimated traffic counts in the two cases was (52.11% and 52.01%) according to me approach, (75.39% and 75.53%) according to OLS approach, and (75.56% and 75.53%) according to GLS approach.

also, to guarantee performance, the results were compared to PTV visum's tflow fuzzy (TFF) and least square (ls) results.

the results show that both the GLS and OLS methods can produce extremely accurate results, with the mean absolute error value approximating the results of the ls method by at least 98%, and the error rate is reduced by approximately 11% over the TFF method.