University of California Transportation Center

Urban economic theories are based on the assumption that workers choose their residences to maximize utility by trading off commuting and housing costs. This means that each urban land-use model will have a corresponding minimum aggregate commuting cost. Unfortunately, most of the minimum aggregate commuting costs required by urban models are quite different from what we observe from actual data. Excess commuting is commuting unexplained by the model; in other words, it is the difference between average actual commute from observed data and average minimum required commute calculated by the model.