Congestion Charging Model The Environment Business has developed a model of the effects of congestion charging on competing retail centres. The model was developed jointly for the DTLR and the BRC to form part of a Congestion Solutions process that could occur between local authorities and retailers located in areas where congestion charging is being considered. We have organised our model into the five areas that we consider to be the most important, illustrated below. The choices of consumers to go shopping generate revenues for shops and possible congestion The existence of congestion affects the decisions of when, where and how to go shopping The changes in spending as a result of these changes to shopping habits affects the location of shops Changes in the location of shops affects the decision to go shopping and what to spend The model contains individual consumers who make independent decisions about where to shop and how to get there. Shops are also able to decide where they wish to locate. The model can be used to determine the effects of introducing a road user charge or a workplace charging levy. It can also be used just as a model of competing retail centres. See some model results.