I recently attended the annual Transport Modelling Forum in London.  Copies of the presentations are available.  I subsequently sent a letter to the editor of Local Transport Today, which has now been published.  The text is as follows.

Your report (LTT 19 June) of the recent Transport Modelling Forum rightly highlighted the study by Denvil Coombe of the 30 regional and sub-regional models that the English regions have available to help inform development in the conurbations.  He found the quality of the models to be very variable, with high levels of validation hard to find.  The conclusion one can draw from Coombe’s analysis is that most models are not at present evidently fit for purpose.

Denvil Coombe’s study was commissioned by the Department for Transport, to its credit.  At present, the models considered are not named, just referred to anomymously.  It seems that the Department intends to publish the report in this form.  But then how does a regional transport authority commission a fresh modelling study, knowing that some models are better than others, but not which is which?   One answer would be to retain the services of Denvil Coombe to advise the procurement, he being the only person outside DfT who knows what’s sound and what’s not.

It would be better if DfT were to publish the report, naming names.  Not only would this be helpful to the regional authorities, but it would put pressure on the proprietors of the less effective models to improve their performance.

I await with interest the Department's decision.