Dr Ian Espada Team Leader Network Operations

Ph: +61 3 9881 1685 ian.espada@arrb.com.au

Overview of the four-step transport demand model

Housekeeping

The duration of this webinar is {one hour}. The presentation will be {40} minutes, and {20} minutes is allocated for questions.

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Content

What is it?

Scope and limitations?

5

Analysis of strategies

Future urban form Future transport

network

Present urban form Present transport

network Future socio-economic

framework Population Economy

Transport demand model

Performance indicators

Accessibility Travel time and cost Environmental and social impacts Safety

Transport strategies Urban development strategy

Port of Hai Phong & Cai Lan

6

-

5,000

10,000

15,000

20,000

25,000

30,000

35,000

1995 2000 2005 2010 2015 2020 2025

all

ca

rgo

(0

00

MT

)

-

500

1,000

1,500

2,000

2,500

3,000

3,500

co

nta

ine

rize

d c

arg

o (

00

0 T

EU

)

All (recorded)

All (High)

All (Mid)

All (Low)

Container (recorded)

Container (High)

Container (Mid)

Container (Low)

All cargo

Containerized cargo

Projected Port Traffic at Hai Phong and Cai Lan NRCTSS (ALMEC 2007)

What is a Transport Model?

Equations representing the choice made by individuals when they travel

Transport models have two defining features

Form: assumptions of behaviour and policy sensitive

Parameters: calibrated from data

e.g. Y = + X

Model form and calibrated parameters are assumed to be valid in the future

7

Menu of modelling techniques

Analytical Simulation

Macro-model Micro-model Macrosimulation Microsimulation

Average delay

Approach flow

EMME, CUBE,

VISUM,

ARRBTraffic, etc.

SIDRA, Austroads

GTM, etc. TRANSYT,

SATURN, etc. Q-PARAMICS,

AIMSUN, VISSIM, etc.

8

Trip purposes

Origin base Home-based

Non-home based

Commonly used classification of trip purpose Go home

Work

School

Shopping & recreation

Others

9

Demand modeling approaches

Home Shop Work Lunch

Home Shop Work

Lunch Work

Lunch Work

Work Home

Home

Home Shop

Activity-based

Trip-based (FSM)

Home Work Lunch Home Shop

Tour-based models

10

Structure of a FSM

Future socio-economic framework

Generation/attraction

Distribution

Mode choice

Route choice

11

Trip generation/attraction

12

Trip distribution

13

Source: MMUTIS, JICA 1999

Mode split

14

Stopher and Meyburg (1975)

Route choice

Multiple trip purposes FSM for one period

G/A

OD

Split

G/A

OD

Split

G/A

OD

Split

Car OD Transit OD

Highway assignment

Transit assignment

Work Shop Etc.

16

Trip End and Trip Interchange

Generation/attraction by mode

Distribution

Route choice

Generation/attraction

Distribution

Mode choice

Route choice

Trip-end model Trip-interchange model

17

Study periods

All day model (24-h or 16-h model)

Peak hour model

Multi-period model

Departure time choice

Time dependent network assignment

18

Perth ROM & STEM

0 10 205 Kilometers0 10 205 Kilometers

ROM 1146 zones STEM 472 zones

19

Link-Node Network

20

Victorian Integrated Survey of Travel and Activity

http://www.transport.vic.gov.au/vista#Survey

21

Limitations of a FSM

No feedback with transportation plans

Socio-economic framework does not change with transport plans

Performance on predicting freight transport is still poor

Intra-zonal trips are not satisfactorily modelled with implications to walking and cycling

Trip chaining is not properly modelled

22

Predict-and-provide?

23

Do-nothing network (2020) Proposed network (2020)

Regional highway network in Northern Vietnam (HAIDEP, ALMEC, 2007)

Reality check

24

Source: Flyvbjerg, Holm and Buhl, 2006, Inaccuracy in traffic

forecasts, Transport Reviews, Vol. 26, No. 1, pp 1-24.

27 rail projects

183 road projects Stated causes of inaccuracies

27 rail projects 208 road projects

Deliberately slanted forecast

Tolled roads forecast

25

PPP project Opening date Forecast daily

traffic in first year

Actual

in 2010

Clem7, Brisbane Mar 2010 94 706 28 061

Lane Cove Tunnel, Sydney Mar 2007 100 000 63 530

Cross City Tunnel, Sydney Aug 2005 70 000 35 000

Westlink M7, Sydney Dec 2005 174 000 126 935

EastLink, Melbourne Jun 2008 234 000 150 738

Thank you for your participation today.

For further information on the topic, please contact:

Ian Espada

+61 3 9881 1685

ian.espada@arrb.com.au

www.arrb.com.au