3.11 Assignment Preparation
It should be noted here that the part of the trip-based model that generates passenger demand has been replaced by DaySim activity-based model. DaySim produces detailed outputs that include information on activities and tours simulated for the synthetic population. In addition, it also produces a simple trip list that has origin, destination, purpose, mode, value of time, and time of day information. This trip list is converted to vehicle trip matrices in Cube using vehicle occupancy rates and are segmented by mode, value of time, and time period. Transit trips by transit sub-modes are also included in preparation for transit assignment.
The ‘Trip Tables for Assignment’ application is run after ‘DaySim’ application and this does precisely as the name suggests, it prepares the vehicle trip tables that will be used in the final vehicle assignment step. This is a new application specifically built and configured for the NERPM-AB model system.
- Application Name = Trip Tables for Assignment
- Application Purpose = Combines activity-based demand from DaySim with the auxiliary demand (trucks and externals) and the JAXPORT freight demand to produce the total regional demand trip tables for use in final assignment
- Primary Input = Internal passenger travel demand from DaySim; auxiliary demand produced and carried forward from preceding NERPM-AB applications (eg. generation, distribution)
- Primary Output = Final Daily, AM, MD, PM and NT period vehicle trip tables for each model period (*.mat)
This application is a simple summation of the vehicle trip demand matrices estimated by the different components of the integrated model system. The application in the NERPM-AB model system is performed using the Cube Voyager MATRIX program. The application combines the light truck, medium truck, heavy truck, the IE and EI vehicle trip matrices, the EE vehicle trip matrices, the JAXPORT freight truck trips and the internal passenger demand matrices from DaySim to produce four (4) individual vehicle trip matrices for the AM, MD, PM, and NT model periods representing the entire 24-hour day.