1. Travel Modelling Group Technical Advisory Committee
May 8, 2013

2. Today’s Agenda Overview of current TMG tools & available resources
TMG Toolbox
EMME worksheets
XTMF
Getting / installing TMG tools
Requirements
Obstacles?
Centroid Connector Generation
TMG Website (tmg.utoronto.ca)

3. Current Tools: TMG Toolbox
Suite of Tools for Emme Modeller

4. Current Tools: TMG Toolbox
Currently contains tools for:
Results Analysis
Validation/Conversion with/to NCS11
Network editing including Centroid Connectors
XTMF-compatible road and transit assignment scripts (converted from original macros)
Python libraries for some common code

5. Current Tools: TMG Toolbox
NCS11
A number of tools to facilitate conversion
Network Editing -> Centroid Connectors
For detailed discussion later
“Copy Zone System” tool for porting centroids + connectors from one databank to another. Produces a shapefile illustrating connectors not copied.
Network Editing -> Transit Networks
“Create Time Period Networks” will be used to generate transit networks for multiple time periods

6. Current Tools: TMG Toolbox
Assignment Tools
Robust, generic ports of major assignment macros for use from Modeller or XTMF
Matrices, scenarios, and attributes no longer are hard-coded
Results saved into user-specified matrices
Transit assignment split into separate assignment and analysis tools / modules

7. Current Tools: TMG Toolbox
Analysis -> Screenlines:
Allows screenlines to be defined by shapefiles
Can be “imported” into the network as extra attributes, or used to extract results “on-the-fly”

8. Current Tools: TMG Toolbox
Scripting tools:
“Execute Python Script” Tool permits the execution of single script files (*.py), with all ‘print’ statements echoed to the logbook.
The “Geometry” library contains functions for integrating Emme networks with geometric operations.
“Screenline” library is the basis of all screenline tools; can also be used for scripting.

9. Current Tools: Emme Worksheets
Transit line viewer
NCS11 VDF Viewer
NCS11 Node Viewer

10. Current Tools: XTMF Capabilities: New features: Four-step models
Network parameter estimation
Mode choice parameter estimation
Network connector optimization
Population synthesis
New features:
Linked Parameters
Integrated documentation

11. Software/Hardware Requirments
TMG Toolbox:
Emme Modeller
XTMF:
Windows XP or newer
.NET framework version 4.0 or higher.
GPU requirements (optional): DirectX 11 graphics card

12. Centroid Connectors
Objective: Create an algorithm for generating centroid connectors for a given network and a given zone system
Challenges:
Easy to define and apply hard constraints, but difficult to define an objective function
Cannot reasonably assume that zone internal roads are not present (especially when applying an older zone system to a newer network)
Not much experience to draw upon in the literature

13. Algorithm Framework
Apply well-defined constraints to the network’s nodes to prevent unrealistic connections (e.g., to highway on- and off-ramps).
Choose from a set of possible centroid connector configurations.
Avoid an algorithm in which processing order matters by avoiding constraints which depend on the connections made by other zones.

14. Algorithm Framework
Feasible Nodes: The set of nodes in the network for which a centroid connection is feasible.
Candidate Nodes: The set of nodes which are candidates for connection to a given zone centroid.
Configuration: A selected sub-set of a zone’s candidate nodes which represents a potential configuration of connectors.

15. Proposed CCGEN steps For all zones
Create the set of feasible network nodes by applying a user-specified criteria.
For each zone
Get the set of candidate nodes by searching the set of feasible nodes (usually based on distance).
Reduce the set of candidate nodes which result in connectors which cross user-specified boundaries.
Reduce the set of candidate nodes to the user-speicifed limit by removing the furthest nodes first.
Iterate through all of the potential combinations of centroid connectors, from one connection up to a user-specified maximum, and calculate a utility value for each.
Create connectors for the combination with the highest utility.

16. CCGEN Utility Function
What is a ‘good’ configuration of centroid connectors? What makes one configuration ‘better’ than another?
Some ideas:
Try to distribute the connectors radially around the centroid.
Try to prioritize certain nodes (i.e., mid-block nodes, or nodes very close to the centroid).
Others…?

17. TMG Website http://tmg.utoronto.ca
All TMG TAC and SC members already have accounts.
Your account is “[First Name] [Last Name]”, and the default password is “ChangePassword” (case-sensitive)