TRACKS_LITE to be launched

TRACKS_LITE has been designed as an easy to use simplified model for use by traffic engineers who need a means of estimating existing and future traffic volumes.

It has been developed specifically to support the link with SIDRA as a low-cost means of integrating the ability of TRACKS to forecast flows with the power of the intersection analysis capabilities of SIDRA. It also provides a way to ‘fill in’ missing counts needed for a SIDRA network using matrix estimation techniques available in TRACKS.

 

Recent Applications

Recent TRACKS applications

The Sydney Emme Assignment model

The recent project undertaken by TDG in Christchurch for the ITUC members to be able to use the RMS Sydney model to provide boundary conditions for the Illawarra models involved conversion of the Sydney Emme assignment model to Tracks so that the external and through trips for the various ITUC models could be extracted without the need for the users to go to the expense of buying Emme licences.  This should have been straightforward but with software nothing ever is.  

The Sydney model has

  • Number of zones                        2,715

  • Number of links                        72,258

  • Number of nodes                     26,743

  • Highest node number              78,275

    Increasing the number of zones was easy. The need to accommodate more than 32,000 links, and node numbers greater than 32,000 (for the technically minded that is the maximum number that can be stored in a 16bit integer word) required finding and re-specifying literally thousands of variables in hundreds of C++ and Fortran routines. Nevertheless, the conversion has been achieved, and the Sydney assignment can now be run in Tracks.

    Part of the project was to compare the results of an equilibrium assignment in Tracks and Emme.

    Of the 56,931 non centroid links, only 863 had flow differences of more than +100 vehicles per two hours and these were largely the result of very small deviations in paths where the travel costs re very similar - mainly in central Sydney. Almost 37,000 links (65%) were within +10 vehicles per two hours.

    Apart from the node and link numbers, the Sydney model conversion forced another change in Tracks. Formerly, intersections in Tracks were limited to 6 legs. Many of the intersections in the Sydney model have four road legs and four centroid connectors coming into the same node. Tracks can now handle 8 legged intersections. These changes were all incorporated into ASSIGN and NEX.

    The general conversion program CONVRT, which converts networks and matrices from a variety of packages into Tracks was modified to convert the Sydney EMME model. Emme can export matrices in a variety of formats, and while CONVRT can handle all that we have seen to date, there may well be formats that we have not yet come across. In fact our experience is that there are subtle format differences for every export. Accordingly, CONVRT has not been included in the release.   

The Waikato Regional Transport Model (WRTM)

TDG were commissioned to update the Waikato Regional Model from 999 zones to 2500. This also required an expansion of all programs that use matrices to be increased in size. In addition, the calibration and application of a multinomial logit mode split model required three new programs to be written. These include

  • BGPREP. This program takes trip and cost matrices by mode, and prepares an input file for Biogeme[2]. Biogeme is a Swiss program that estimates parameters for logit models. At present BGPREP is specific to the WRTM model but can readily be adapted for other applications.

  • LGPREP. This program takes the trips generated by the WRTM household category model and splits them into trips from car owning and non-car owning households.

  • MULTIN. This program applies the WRTM multinomial logit mode split model.

     

The Shoalhaven-Kiama Model Build (2014)

The model specification called for four different household types to be included in the Trip Generation stage of the model – specifically standard houses, apartments, retirement complexes and holiday homes. Accordingly TRPGEN has been modified to accommodate this, for both productions and attractions. TDG have completed the model build, and it has been peer reviewed by Bitzios Consulting

 The 2017 release

The 2017 release has been prepared and a dropbox link will be provided on request.

Because of the wholesale changes that have occurred with the suite, while we have done our best to check backward compatibility, we have been programming long enough to know that nothing is ever 100% tested. Accordingly, we would suggest that you rename, or backup your existing TRACKS directory before you load the 2015 release. That way you can easily copy back any particular program that is giving an issue. Please send us the parameter and data files so that we can fix any bugs.