Avenue dynamic count files

The count file format to be used with Analyst Drive is given in Figure 12. The order for each line of the file follows in order node A, node B, screenline number, count(k, k=1, #intervals). The dynamic count files should be placed in the SL File block positions just as in the static case, the declaration of the ODTYPE parameter tells the Analyst Drive program to read the file as the static or dynamic version. Currently, one screenline count file must be provided for each dynamic OD matrix file used in the estimation. In the future we anticipate that dynamic estimation will be possible with fewer count sets than the total number of user class OD matrices to be estimated using the same methods as with the static model of Analyst Drive, but for now multiple count files will have to be provided for multiple user classes.

Figure 12: Screenshot of a dynamic screenline count file used by Analyst Drive.

Note: Avenue Dynamic count files used by Analyst Drive should not contain any zero-count values as this causes a divide-by-zero in the algorithm. If the user truly desires to use zero-count values in the assignment, then it is recommended that they change the count value in the screenline count file used by Analyst Drive to 0.1. This will allow the program to maintain data alignment with minimal impact to the estimation process. If a zero-count is found in the dynamic count file, an error will be thrown and the program will be aborted. For more information, please see Zero count screenline values on page 71.