> population and land-use patterns... are two of the most important variables in any TDM [Travel Demand Model] All models are based on assumptions. Revisiting

> population and land-use patterns... are two of the most important variables in any TDM [Travel Demand Model] All models are based on assumptions. Revisiting those assumptions should be a continuous process that forms a tight feedback loop, especially given the long timelines and large capital costs involved with civil infrastructure projects. If population and land-use assumptions are the key factors then the important questions should be how these assumptions will be validated and how often. These questions seem to be missing from the article.