Table of Contents

Transit Assignment

The first step recommended is to calibrate the Transit Assignment models. If you are not familiar with these models please review their documentation here.

You can find the Transit Assignment model in GTAModel V4.1 at Pre Run/Execute Transit Assignment or Post Iteration/Run Network Assignments. Inside each Transit Assignment model, there are 6 modules that you may calibrate with as shown below:

  1. Fare-based Transit Network (FBTN)
  2. Boarding Penalities
  3. Transit Demand
  4. Walk Perceptions
  5. Surface Transit Speed Updating Models (STSU)
  6. Transit Time Functions (TTF)

Fare-based Transit Network (FBTN)

You can change the fare scheme by modifying the Fares.xml file in Generate FBTN module, which is stored in the input directory Scenario-Transit Fares/Base.

In the Emme network, it is assumed that boarding and transfer fares are stored in the link attribute '@lfare*', and in-line fares are store in the transit segment attribute '@sfare*'.

Boarding Penalities

The mode and agency-specific boarding penalty scheme is adopted to minimize the Root-Mean-Square Error (RMSE) of observed and modelled boardings/alightings. You can find the list of modules to adjust the boarding penality for a specific mode or agency in Assign Boarding Penalities. Each mode or agency module contains five parameters.

Parameter Description
In Vehicle Time Perception Ratio of perceived travel time compared to true travel time
Label Name of the specific mode/agency
Line Filter To filter the transit lines for the specific agency
Mode Filter To filter the transit lines for the specific mode
Penalty Boarding penalty to apply for the mode/agency

Transit Demand

You can change the transit demand matrix in Import Transit Demand module, which is generated from Mode Choice/Post Household Iteration/ and stored in the output directory Demand.

Walk Perceptions

A list of modules to change the walk perception can be found in Transit Assignment/Classes for 5 types of links, including Toronto/Non-Toronto, PD1, and Toronto/Non-Toronto Centroid Connectors.

Tip

The detailed description of the five types of links can be found here.

Each module contains two parameters.

Parameter Description
Filter An filter expression for links that the perception applies to
Walk Perception Value Walk perception on links

Surface Transit Speed Updating Models (STSU)

You can modify the surface transit speed updating models in Surface Transit Speed Model module. GTAModel V4.1 has included Local Bus, GO Bus, and Streetcar. You may add as many SurfaceTransitSpeed modules as needed. Each module contains 7 parameters.

Parameter Description
Alighting Duration Alighting time in seconds per passenger
Boarding Duration Boarding time in seconds per passenger
Default Duration Default duration time in seconds per stop
Global EROW Speed The speed to use in segments that have Exclusive Right of Way for transit and do not have @erow_speed defined. This includes accelaration and decelaration time.
Line Filter Expression To determine which lines will get surface transit speed updating applied to them (Leave it BLANK to select all lines)
Mode Filter Expression To determine which modes will get surface transit speed updating applied to them (Leave this and Line Filter BLANK to select all lines)
Transit Auto Correlation The multiplier to auto time in order to find transit time (i.e., the ratio of Transit Running Time to Auto Time)

Transit Time Functions (TTF)

A list of modules to change the Transit Time Functions (TTF) can be found in TTF module. Currently in GTAModel V4.1, there are five types of TTF functions to apply for various services/modes.

Tip

A more detailed introduction to TTF functions can be found here.

Each module contains three parameters.

Parameter Description
Congestion Exponent The congestion exponent term to apply to this TTF
Congestion Perception The congestion perception to apply to this TTF
TTF The TTF number to assign to (e.g., 1 means TTF1)