Static OD Estimation Minimizing the Relative Error and the GEH Index

One of the essential quantities in macro traffic simulation is the ‘who goes where’ OD matrix. This is usually estimated through an optimization problem of minimizing the squared differences between observed and simulated traffic counts. The choice of the mean square error loss is due to its good statistical properties and the fact that the related quadratic optimization problem is easy to deal with. However, in many applications following the recommendations of validation criteria suggested in many guidelines published by different road administrations, such as FHWA in USA, ARRB in Australia or Highways Agency in UK, the quality of an static OD adjustment is assessed with other quantities such as the relative error or the GEH index. In this paper we estimate OD matrices minimizing directly the mean geh or mean relative error.