Case Study:

Sacramento, California

Conclusions

Limitations of Land Use Model

• Like most transportation-land use models, MEPLAN uses large zones and sketch networks, potentially leading to different travel and emission results than the Sacramento model which is much more detailed. Specifically, the representation and accuracy of projected vehicle volumes, speeds, distances, and thus emissions, is limited. In the Sacramento case, SACOG staff have expressed concern over using two different models that produce different results. If land use feedback is to be incorporated into travel modeling for regional planning, conformity analysis, or other purposes, an approach will be required that uses a land use model in iteration with a travel model that includes a detailed network and zone system.

• The tradeoff for a detailed representation of land markets and inter-industry interactions is that a large amount of data is required to develop and calibrate the model. While MEPLAN can be customized based on locally available data, many regions will not have adequate data to take full advantage of the modeling capabilities offered. The application in Sacramento would have been strengthened through the availability of floorspace data as well as data from multiple years. The project demonstrates, however, that a useful model of urban land use and transport interaction can be developed in a United States metropolitan area using existing data sources.

• Behavior is modeled at an aggregate level (groups of people or businesses by zone) rather than at a disaggregate or individual level. This masks differences in behavior among individuals or subsets of the population. While the aggregate approach is less realistic, it is much simpler than modeling an entire heterogeneous market.

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