Dear Transportation Colleague: The Census 2000 County-To-County Worker Flow Files have just been released. These data contain the number of workers 16 years old and over who commute to work. The counts give the number of workers traveling within or between counties in the 50 states and the District of Columbia, plus travel to workplaces outside the U.S., such as Puerto Rico or a foreign country. If you or others simply want to inspect and/or query the data, you can use a web mapping application at (http://www.caliper.com/countytocounty). This application of TransCAD for the Web creates desire lines and produces tables for any selected county. Currently only flows of 50 workers or more in or out of the county are shown, to reduce clutter. If you are a TransCAD user, we made it easy for you to obtain these data. We converted it to a TransCAD matrix that you can download at (http://www.caliper.com/download/2kresco_us_mtx.zip). The ZIP archive is 644KB, and the unarchived matrix will be 42.2MB. The rows are the residence counties, and the columns are the workplace counties (and workplaces outside the U.S.). The row and column IDs are the FIPS codes for the counties (and workplaces outside the U.S.) as integers. The one matrix in the file contains the number of workers 16 years old and over who commute to work. The ZIP archive also contains a matrix view that you can use to start working with the matrix quickly, based on the medium-resolution county geographic file (ccCounty_M.CDF); make sure that you have that geographic file open as a map layer before opening the matrix view. The matrix view uses a formula field called CountyNum, created with the formula S2I(County), to label the matrix with the county names. You can also use this formula field as the ID field when you use the Tools-Geographic Analysis-Desire Lines command to create desire lines between selected counties. If you have any questions, please feel free to contact us by e-mail at info(a)caliper.com or by phone at 617-527-4700. Peter ---------------------------------------------------------------- Peter Van Demark Director of GIS Products and Training Phone: 617-527-4700 Caliper Corporation Fax: 617-527-5113 1172 Beacon Street E-mail: peter(a)caliper.com Newton MA 02461-9926 Web site: http://www.caliper.com