Data Availability and Model Form

摘要: Data are essential for any empirical modelling effort. In freight transport, obtaining good data can be a challenge because of the difficulty to observe processes directly, often proprietary nature logistics data, and relatively poor acquisition infrastructure. this chapter we review different sources modelling, including trade, transport by modes transport. We discuss which used models. every practical situation, limitations will remain. two main strategies overcome them: adapting model simplified form estimating missing from available information. The concludes with listing some challenges research into future. © 2014 Elsevier Inc. All rights reserved.