1

Developing a methodology for network simulation

E*Space ConferenceNaples and Benevento June 2005

Colin Arrowsmith1, Bob Itami2 and Silvester (Sungchan) Kim1

1Department of Geospatial Science, RMIT University

2GeoDimensions Pty. Ltd.

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Methodology objectives

• to understand spatial behaviour of mobile objects along networks

• to develop typical itineraries for various types of mobile objects

• to model mobile objects along networks given differing environmental conditions

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Rationale

• predicted increases in traffic flow along networks

• physical constraints results in loss of amenity and threats to safety

• need to test management options under differing scenarios

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Methodology

• develop inventory of network

• survey design - detection, observation and recording of mobile objects

• developing typical itineraries for dynamic objects

• spatial analyses of movements

• identification of types of dynamic objects

• modelling movements

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Develop inventory

• base spatial information acts as datum for analyses and modelling

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Survey design – attributes required

• position

• duration

• sequence or “itinerary”

• flow

• speed and orientation

• type of object

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Survey techniques

• questionnaire and interviewing

• video monitoring

• detectors and sensors

• tracking mechanisms including GPS

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Itinerary determination

• identify network sequences

• classify network sequences

• statistical probability analyses

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Spatial analyses

• extract topological linkages

• apply segmentation for analyses– duration

– velocity

– diurnal patterns

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Classification of types

• classification of object types using – cluster or

– data mining techniques

– direct observation

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Simulating movements and behaviour

• agent-modelling– autonomous agents

– linked to GIS

– agent-rules

– wayfinding

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Case study 1 – Loch Ard Gorge

• objective– to identify typical spatial behaviour patterns at a popular

tourist attraction

• rationale– increased visitation to tourist sites with constrained physical

parameters

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Develop inventory for Loch Ard Gorge

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Attractions

• 26 point attractions– lookouts– river– car parks

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Survey design

• GPS survey

• questionnaire survey

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The GPS receivers used

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GPS survey attributes

Attribute Units

   

point_id integer

survey_id integer

Easting AMG66 metres

Northing AMG66 metres

Date dd/mm/yyyy

Time hour:min:sec

Altitude metres

Leg_length metres

Leg_time seconds

Leg_speed kmph

Bearing Whole degrees

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Topological linkages

4 (3)

19 (7)

18 (7)

16 (6)

17 (6)

12 (4)

15 (5) 10 (4)

11 (3)

8 (2)

7 (4)

6 (4)5 (3)

3 (2)

2 (1)

1 (0)

9 (3)

14 (6)

13 (5)

A

DDC

BG

F

E

I

H

7 (4) Node number (associated number)

Labelled sequence node

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Describing spatial-temporal data

• development of regions to assist in describing movement patterns

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Nodes visited

Number of sequence nodes visited

Number of participants

Average duration (mins)

     

1 3 65.67

2 21 38.14

3 40 54.20

4 17 67.94

5 10 87.00

6 8 128.00

7 1 111

8 1 105

9 1 212

Average = 3.48 102 65.12

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Visitor typologies

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Simulation modelling

• RBSim3 is a computer model

• maintains a database of visitor experiences through a simulation

• itinerary can be built for an agent

• agent movement is modified by the changing conditions of a network

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RBSim Simulator

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Case study 2 – River Traffic Study

• objectives

• rationale

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Objectives

• to determine the capacity of the Yarra and Maribyrnong rivers to meet growing demands

• identify management systems and infrastructure to control boat traffic in a safe and sustainable manner

• develop a management strategy to control river traffic

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Rationale

• broad range of users and vessels with different patterns of use

• knowledge of impacts of different watercraft on environmental and social conditions is uncertain

• volumes of traffic predicted to increase substantially

• capacity of river has not been defined

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Inventory development

• river depth

• bank conditions

• land and water facilities

• adjacent land use

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Inventory development

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Survey design

• interviews with user groups

• new river counts

• published schedules

• GPS tracking

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GPS Tracking

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Topological linkages

A

KL

B

M

C

B1 F

G

D E

I

J

H

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Patterns of movement

AAA (4)

AABB (1) AABBA (1)

AA (39-28) AAB (6-1) AABCB (2) AABCBA (2)AABC (4-1)

AABCD (1) AABCDE (1)AAB1 (1)

ABAA (1)ABA (4-2)

ABAB (1)

ABBAA (1) ABBAAA (1)ABBA (2)

ABB (5-2) ABBAB (1)

ABBB (1) ABBBB1 (1) ABBBB1A(1) ABBBB1AA(1)

ABCBA (4-3) ABCBAB (1)ABCB (5)

A (115) ABCBB (1)AB (66-19)

ABCCB (4) ABCCBA (4-3) ABCCBABC (1)ABC (35-12) ABCC (9-3)

ABCCC (2-1) ABCCCB (1) ABCCCBA (1)

ABCDED (2) ABCDEDC (2) ABCDEDCB (2) ABCDEDCBA (2-1) ABCDEDCBAA (1)ABCD (8-3) ABCDE (5-1)

ABCDEED (1) ABCDEEDC (1) ABCDEEDCB (1) ABCDEEDCBA (1)ABCDEE (2)

ABCDEEE (1) ABCDEEEE (1)

ABG (3) ABGH (3-2) ABGHH (1) ABGHHG (1) ABGHHB (1) ABGHHBA (1)

AB1B (2-1) AB1BC (1) AB1BCD (1) AB1BCDE (1) AB1BCEECB (1) AB1BCEECBA (1)AB1 (9-6)

AB1B1 (1) AB1B1B (1) AB1B1BC (1) AB1B1BCC (1) AB1B1BCCB (1) AB1B1BCCBA (1)

AK (1) AKA (1) AKAB (1) AKABC (1)

TOTAL 115 115 62 38 27 18 10 7 3 2

BAAA (1)BAA (10-4)

BAABA (1)BAAB (5-3)

BA (42-28) BAABB (1)

BAB (4-3) BABC (1) BABCL (1) BABCLK (1) BABCLKL (1) BABCLKLK (1) BABCLKLKL (1) BABCLKLKLK (1)

BBA (2) BBAA (2-1) BBAAB (1)BB (10-4)

BBBA (1) BBBAB (1) BBBABB (1)BBB (4-2)

BBBB (1) BBBBB (1)

B (64)BCB (1)

BC (10-1) BCC (3) BCCB (3) BCCBA (3-2) BCCBAB (1) BCCBABC (1)

BCDC (1) BCDCB (1) BCDCBA (1) BCDCBAA (1) BCDCBAAB (1) BCDCBAABC (1) BCDCBAABCD (1)BCD (5-3)

BCDE (1) BCDEE (1) BCDEED (1) BCDEEDC (1) BCDEEDCB (1) BCDEEDCBB1 (1) BCDEEDCBB1A (1)

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Boat types

• rowing boats

• commercial craft

• government vessels

• motor charter

• tug boats

• motor private

• ship

• non-motor sail

• sail under motor

• non-motor oar

• non-motor paddle

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Conclusions

• developed a consistent methodology that can be applied to model mobile objects along different networks under different management scenarios