Importance of Field Location to the Nature of Data
Almost all traffic stream models attempt to explain the behavior of traffic over the full range of operations, from un-congested free flowing traffic, to operations at capacity and finally to congested stop-and-go operations. In turning the models from abstract representations into numerical models with specific parameter values, an important practical question arises: can one expect that the data collected will cover the full range that the model is intended to cover? If the answer is no, then the difficult question follows of how to do curve fitting (or parameter estimation) when there may be essential data missing.