Floridas New Transit Modeling System

1
Floridas New Transit Modeling System

• Huiwei Shen, Yongqiang Wu Dave Schmitt
• 11th TRB Planning Applications Conference
• Daytona Beach, Florida May
  6th-10th, 2007

2
Background/Context

• Florida is one of few states that standardizes
  modeling practices
• Original standards developed in early 1980s
• Original transit model needed re-evaluation
• Florida MTF decided in 2005 to convert models
  from Tranplan to Voyager
• Increasing pressure on transit models from New
  Starts

3
Work Task Overview

• FDOT needed an updated transit model using PT
  that was mindful of the
• Existing standards
• User planner needs
• New/Small Starts FTA guidance
• Features capabilities of PT Voyager
• Key challenge PT was largely untested unused
  at the time

4
Technical Challenges

• Leg vs. link
• Multi-path path-builder
• Always finding a transit path

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Leg vs. Link
Centroid
Station
Rail Line
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Transit Link Example
Centroid
Walk-access connector
Sidewalk link
Station
Rail Line
Sidewalk link
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Transit Leg Example

• Two requirements
• All connectors must connect transit stop to
  transit stop or transit stop to centroid
• Connectors must spider highway network

Centroid
Walk-access leg
Station
Rail Line
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Leg vs. LinkImplications

• Could not use link-based access connectors
• Spidering along highway network conflicts with
  percent walk computations developed in GIS
• Ubiquitous vs. specific access
• Requires program to coordinate percent walks
  walk-access connectors
• Lack of any walk-access connectors implies no
  real transit access ? re-set percent walks to zero

9
Technical Challenges

• Leg vs. link
• Multi-path path-builder
• Always finding a transit path

10
Transit Path-Builders

• Two types single-path multi-path
• Single-path
• Exclusively available in Tranplan, Minutp TP
• Dominant path-builder in Florida US
• Multi-path
• Available in TransCAD Cube-Voyager (PT)
• Becoming more prevalent

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Multi-Path vs. Single-Path
Rail/Shuttle
Local Bus
O
D
Express Bus
Also loading percentages!
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Multi-Path Builders

• Advantages
• Reflect sensitivities that would otherwise
• Be impossible in single-path builders, or
• Create inconsistencies between the path-builder
  mode choice model
• Offer better consistency between path-builder
  mode choice weights
• Unknowns
• How to
• Design a multi-path model
• Coordinate it with the mode choice model
• Calibrate validate
• Introduce a new transit mode
• Whether they meet FTA New/Small Starts guidance
• Whether they work as intended/desired

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Happenings

• Citilabs added a best-path switch to PT in
  summer 2006
• Addresses FTAs New Starts quality control tests
• Mimics single-path builder from Tranplan
• Not compatible with all parameters/keywords
• Initiated testing different model setups
• To provide empirical data to assist with
  FTA/Citilabs discussions
• Help determine best design for a PT-based transit
  model
• Identify any software or design-related issues
  early on

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Transit Model Setups
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Findings

• Developed PT Best-path setup that mimics
  PT-TRNBUILD results
• Multi-path model design results very different
  from Best-path TRNBUILD
• Further research needed to define multi-path
  model setup
• Recommendations
• Short-term proceeding with PT Best-path setup
• Separate guidelines for General New/Small
  Starts use
• Long-term track evolving FTA guidance, industry
  progress PT updates goal - evolve to multi-path

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Technical Challenges

• Leg vs. link
• Multi-path path-builder
• Always finding a transit path

17
Finding a Transit Path

• Previous path-builders like Tranplan TRNBUILD
  would not develop a transit path if walking is
  faster
• Skim would contain all zeros or just have zero
  IVT
• No similar logic in PT
• It does not allow the use of consecutive
  non-transit legs
• If any transit is available, it will always find
  a transit path no matter how crazy

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Finding a Transit Path Example

• Take walk connector 137-2909
• Ride all-stop north to 2849
• Take escalator up to 7849
• Ride skip-stop south to 7909
• Take walk connector 7909-136

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Finding a Transit Path Solution

• Generate all-walk connectors from all zones to
  all zones
• Compare all-walk time/utility to transit
  skim/utility
• If all-walk time is less onerous, zero out
  transit skim
• Can be done post skimming or in mode choice

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Status

• Developed framework documents to summarize key
  points
• Theoretical coordination of individual parts
• Application parameter settings, technical
  details
• Both available on www.fsutmsonline.net
• Developed training model with full transit model
• Transit model training workshop June 4-7, 2007

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Special Thanks

• James Ryan Nazrul Islam, FTA
• Wade White Dudley Morrell, Citilabs
• William Woodford, Jeffrey Bruggeman Ashutosh
  Kumar, AECOM Consult

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• Thank you!