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webinar on 4 step modelling
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Dr Ian Espada Team Leader Network Operations
Ph: +61 3 9881 1685 [email protected]
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.
All participants will be emailed a PDF copy of the presentation at the conclusion of the webinar.
Go To Webinar functions
You can ask questions at any time by typing them in the question box, I will answer them in the question time at the end of the presentation
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
www.arrb.com.au