Users can now choose to estimate warm up period matrices along with regular time period matrices in the dynamic estimation process. In order to do this the input matrix file should be the same as the one input into AVENUE assignment program, there should be counts included in the screenline file for every matrix tab present in the matrix file, and the WARMCNT option should be set to true. If these conditions are met, the Analyst Drive program will treat warm up period counts as regular time periods and they will be estimated in the same manner. If the user does not have count sets for the warm up period but still wishes to estimate warm up period matrices for improved performance, it is recommended to simply use copies (or perhaps appropriately scaled copies) of the count set from the first time period for each warm up period. Note: If the WARMCNT option is set to true the program will automatically set the WARMAT and WARMUP options to false.