In addition to traffic data, other travel behavior data is important for travel demand forecasting. Origin-Destination (O-D) data is one of the most important pieces of information for any model development and planning study, particularly for managed lanes, Interchange Access Requests (IARs), and transit studies. Products from the US Census Bureau, such as Census Transportation Planning Products (CTPP) derived from American Community Survey (ACSs), Longitudinal Employer-Household Dynamics (LEHD) data, and National Household Travel Survey (NHTS) O-D data developed by the Federal Highway Administration (FHWA) offers free and current information at Census Block level or Traffic Analysis Zone (TAZ) level. Regional household travel surveys and transit on-board surveys offer another major source of information.