Transportation planning is concerned with the development of infrastructure, definition of policies, and other activities based on a plan to meet future transportation needs. Transportation planning activities must consider a range of factors such as land use and land value, capacity of the transportation network, and public safety. The analyses performed in support of transportation planning activities must therefore utilize and combine a wide range of information. In order to effectively perform these analyses the data must be correctly combined. This requires a clear understanding of the terms used to describe the data, as well as how they relate to one another; the semantic integration of this data is just one of several clear applications for ontologies in the transportation planning domain. In this project we have developed a suite of ontologies for representing information used in transportation planning.