7 December 2016

CSTM Improvements___

AITPM – Canberra – 11 May 2017

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Introduction

Josh Everett – SMEC AustraliaWorked on modelling in Canberra for 11 years

Used TransCAD, then EMME, now back to TransCAD

Presentation StructureCSTM

Updates to the CSTM

Calibration/Validation of the CSTM

Hopefully time for questions

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4-step strategic transport model

824 Zones

28,000 Links – 6 categories

102 Bus Routes (87 AM, 90 PM) plus school buses

Four land use types: Population, Employment, Retail Space, Enrolments

Based on generalised cost function

CSTM Structure

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CSTM – The Four Steps

Trip GenerationFixed generation rates for each of six purposes based on population

Home Based trips are modified by socio-economic factors

Trip DistributionTrip totals apportioned by land use

Three different gravity models – Work, Education, Other

Mode ChoiceMulti-level binomial structure for Work, Education, Other

Includes Car, Bus, Bicycle and Park & Ride

Traffic AssignmentEquilibrium assignment with link-based delay

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TransCAD is a native GIS program

More intuitive user interface than EMME

Object oriented coding environment

Includes all procedures as functions instead of terminal script

Uses different database structure, 2-way links

CSTM converted to TransCAD 7 model

Retains model structure and flow

Utilises built-in TransCAD functions where necessary

Update: TransCAD

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Input Data Update

Converted road network to TransCAD format

Reviewed and updated 2011 and 2016 road networks

Updated 2016 public transport network with actual –imported directly from GTFS

Included actual bus stop locations from GTFS

Updated future road networks with latest capital works projections, including 2041

Included “Town Centre Roads” with lower speed and capacity to approximate friction and congestion

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Previous CSTM used 2-hour trip rates modified to 1-hour using 65% assumption

Updated using trip generation rates calculated from Household Travel Survey

New 1-hour rates are 74% of 2-hour rates

Updated directional distribution for 1-hour

Trip Generation Update

Trip Purpose

Updated 2011 AM(One hour)

2011 PM(One hour)

Rate Proportion Rate ProportionHBW 0.112 24.5% 0.089 24.7%HBE 0.092 20.2% 0.013 3.6%Other 0.253 55.3% 0.258 71.7%HBS 0.006 1.4% 0.045 12.4%HBO 0.124 27.1% 0.114 31.8%NHBEB 0.005 1.2% 0.006 1.6%NHBO 0.117 25.6% 0.093 25.8%

All 0.457 100% 0.359 100%

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Model uses inverse exponential distribution:

𝑃𝑖𝑗 =1

𝑒𝑝𝑐𝑘= 𝑒−𝑝𝑐𝑘

Calibrated to survey data using iterative minimisation of RMSE

HBW used Census Journey-to-Work data (24 hour)

HBE used ACT Government school enrolments (missing private schools, CIT, university)

Other used Household Travel Survey

Generated K-factor matrices to better fit data

Trip Distribution Update

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Trip

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Trip Generalised Cost

Calibrated Gravity Curves

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OTH PM

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Gravity Curve Coefficient

Exponential Gravity Curve Calibration

HBW HBE OTH AM OTH PM

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Previously updated mode choice to include bicycles and Park & Ride

Modified generalised cost component weights to match NGTSM

Updated fares, including different fares by purpose, and removed the distance-based fare structure

Updated parking costs by travel purpose

Updated bicycle coefficients

Currently working on future PT network

Mode Choice Update

Total Person

Trips

Motorised

Person Trips

Bicycle

Person Trips

Car Person

Trips

Park & Ride

Person Trips

Enhanced

Transit Trips

Bus Person

Trips

Additional Bus

Person Trips

Additional Car

Person Trips

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No major changes to assignment

Conical function for link delay with interrupted/uninterrupted capacity modifiers

Uses TransCAD’s built-in PT assignment, including Park & Ride

Tighter convergence threshold to meet validation criteria (from 2% to 0.1%)

Assignment Update

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PM Peak Model

New PM peak model for all yearsCalculated new trip generation rates based on Household Travel SurveyPM peak has 79% of AM Peak trips, lower than expectedMain reduction in trips due to educationNew PM public transport networkWork and Education gravity coefficients same as AM, Other uses different coefficientPark & Ride disabledRoad network almost the same, except for school zones

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Developed new validation criteria in association with EPSDD based on VicRoads, RMS and UK DfT standards

Assignment convergence checks that assignment equilibrium has been reached

Feedback convergence checks that sufficient model iterations have been used

Screenline volumes are total volumes across district screenlines

Link volumes are individual volumes at district screenlines

Public transport OD matches model trip matrix to ticket data

Validation Criteria

Stage Source Criteria Threshold

Assignment Convergence

VicRoads/UK DfT

RGAP, and < 1%

RAAD, or < 1%

AAD, or < 1 veh/h

%Diff < 5% > 95%

Feedback Convergence

VicRoads

%RMSE, or < 1%

Max GEH < 2

ScreenlineVolumes

%Diff ±50𝑉−0.3953

Link Volumes

VicRoads/RMS NSW

R² > 0.9

%RMSE < 30%

VicRoads

Slope 0.9 – 1.1

GEH < 5* 50%

GEH < 10* 80%

Public Transport OD

-R² > 0.9

Slope 0.9 – 1.1

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Screenline Validation

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Observed Volume

PM Screenline Validation

Difference Minimum Maximum

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AM Screenline Validation

Difference Minimum Maximum

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Criterion TargetOriginal

2011 AM

Updated2011 AM

2011 PM

R² 0.9 0.83 0.93 0.89Slope 0.9-1.1 0.94 0.95 0.97%RMSE < 30% 43% 28% 32%GEH < 5 50% 33% 50% 51%GEH < 10 80% 64% 73% 70%Average GEH

- 9.2 6.7 7.1

Linkflow Validation

y = 0.948xR² = 0.9255

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Observed Volume

AM Peak Comparison of Car Volumes on Screenline Links

y = 0.9679xR² = 0.8869

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Observed Volume

PM Peak Comparison of Car Volumes on Screenline Links

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Gathered OD data from MyWay ticketing

Used trips that have mid-point between 8:00-9:00AM

Joined transfers into a single OD trip

Compared model and ticket data at a district level

PT OD Validation

y = 0.9763xR² = 0.9934

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Observed Trips

AM Peak Public Transport Trips by District

y = 0.9979xR² = 0.9896

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PM Peak Public Transport Trips by District

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Future Upgrades

Native TransCAD functions

Travel DataHousehold Travel Survey

Traffic count program

Input DataSeparated land use – Education, Retail, Employment

Intersection delay

Future Travel BehaviourLight Rail

Autonomous vehicles

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Questions?