Transcript Preferred citation style - Institute for Transport Studies

Preferred citation style
Axhausen, K.W. (2001) Social networks and travel behaviour,
ESRC Workshop „Mobile network seminar series - Seminar 2:
New communication technologies and transportation systems“,
Lucy Cavendish College, Cambridge, February 2002.
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Social networks and travel behaviour
KW Axhausen
IVT
ETH
Zürich
February 2002
A word of warning
An engineer talking about daily life and its underlying social
structures puts himself at risk.
I am happy to take the risk and look forward to the critique and
comments, as
• We need to underpin our travel behaviour models with a
better understanding of the social structures of daily life
and, as
• We implicitly forecast/speculate about them when we predict
travel behaviour over long time horizons, anyway
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A look back: Productivity growth since 1000 (W Europe)
3.00
Galor und Weil (2000)
Growth rate [%/year]
2.50
Productivity
Population
2.00
1.50
1.00
0.50
0.00
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
Year
4
A look back: pkm/day since 1850 (France)
50
Gruber (1998)
km/Person and day
40
Motorised individual modes
Public transport
Slow modes
30
20
10
0
1840
1860
1880
1900
1920
Year
1940
1960
1980
5
A look back: GDP, Car and telephone ownership (CH)
600
Telephone
Cars
GDP
Mobile phone
Internet user
500
400
250
200
0
0
1890
1910
1930
1950
1970
1990
Year
6
GDP (1913 = 100)
Number/1000 residents
750
A look back: Average consumption of housing (CH)
Gross area/head [m2]
60
45
Rumley (1984); Keller
30
Centres
Agglomeration
Regional centres
Rural villages
Mountain villages
Switzerland
15
0
1950
1960
1970
Year
1980
1990
7
A look back: Household size (CH)
5
Mean household size []
Siegenthaler and Ritzmann-Blickenstorfer (1996)
6
4
3
Central Switzerland
Alpine cantons
NE - Switzerland
NW - Switzerland
Romandie
Switzerland
2
1
0
1850
1870
1890
1910
1930
Year
1950
1970
1990
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Look back: Distribution of personal time (UK)
100%
Gruber (1998)
Lifetime share [%]
80%
Retirement
Leisure and other
Work
Higher education
Childhood and schooling
60%
40%
20%
0%
1860
1880
1900
1920
1940
Year
1960
1980
2000
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Summary for the look back
Extraordinary income streams have been created and are
consumed (in part) as
•
•
•
•
Travel (Speed)
More (and dispersed) housing
Long-distance communication
Longer lives with less work
• Independence/Isolation
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Daily life: Trip purposes (Uppsala 1971/Karlsruhe 1999)
Return home
Leisure
Work
Daily shopping
Private business
Schlich and Schönfelder
Education
Long-term shopping
Pick up/drop off
Uppsala (weighted)
Karlsruhe Mobidrive
Work-related business
Other
0
10
20
30
Share of all trips [%]
40
50
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Daily life: Leisure (Uppsala 1971/Karlsruhe 1999)
Meeting friends
Going out in the evening
Active sports
Going for a walk and hiking
Schlich and Schönfelder
Other
Club meeting
Excursion: Culture
Uppsala (weighted)
Window Shopping
Karlsruhe Mobidrive
Meeting relatives
0
10
20
30
Share of all leisure trips [%]
40
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Schlich
Daily life: Rythms in Uppsala 1971/Karlsruhe 1999
13
König
Daily life: Rythms in Karlsruhe 1999 (56 day survey period)
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Schönfelder
Daily life: Local activity space of a car (Borlänge 2001)
Locations visited during a
3 month period by one car
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Daily life: Example activity spaces (Karlsruhe 1999)
Schönfelder
Ellipses cover the
95% confidence
intervals of the
locations visited
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Summary: Daily life
Households are self-selected/trapped into the vector of
• Home location
• Work/school locations
• Mobility tools
Dominant shares of
• Leisure trips
• Household maintenance trips
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Social networks: Draft categorisation
•
•
•
•
•
•
Family
Friends
Hobby (Animal care)
Sport
Civic engagements
Church
• Neighbours
• School/education
• Work (one or multiple networks ?)
• (Military/Civilian service)
• Service providers
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Social networks: Possible transport questions
• Physical spatial-temporal coherence/overlap (constraints)
• Replacement of physical and telecommunication-based
contact
• Interaction frequency and spatial reach
• Interaction and information/knowledge transfer
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Question of spatial coherence (Network 1)
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Question of spatial coherence (Networks 1 & 2)
21
Question of spatial coherence (Network 1, 2 & 3)
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Social networks: Possible sociological questions
• Openness/replacement dynamics of the membership
• Structure and definition of the network boundaries
• Revival of contact/repair of links
• Shared skill/learning
• Transfer/transmission of reputation
• Transfer of resources/social capital
• Spatial and social reach (“6 degrees of separation” ?)
• (Time/money/social capital) Cost of maintenance
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Social networks: Hypotheses
1. Local spatial-temporal coherence is lower than 1950
Why ?
• The unity of work, residence and „Sozialmileu“ has been
broken for most people (e.g. long-distance commuting)
• Educational/employment paths are less uniform (in space)
• Mass customisation in travel (car), consumption and leisure
(channel flood in entertainment)
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Social networks: Hypotheses
2. The number of the current members is larger than in the past
Why ?
• Money costs of contact have been dramatically reduced
(telephone, email, letter/xeroxing)
• Easier projection of self (email, xeroxing) allows more social
grooming (Dunbar’s about 100)
• Time/money costs of in-person contact with spatially distant
contacts have become – relatively – affordable (i.e. cheap
long-distance travel)
2* Statements about the contact intensity distributions are difficult,
as the increase in leisure time might balance the larger number
of members
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Social networks: Hypotheses
3. Time costs of network maintenance are larger than in the past
Why ?
• Less chance of chance encounters
• Lower local spatial network densities
• Less opportunity to use proxies for messaging
• Higher search costs (locating the person) (but for email,
mobiles, answering machines)
• Higher time costs to get to most members of the net
• Longer catching-up times
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Hypotheses visualised (Networks 1, 2 & 3)
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Social networks: Externalities
• Stronger selectivity ?
• Less local inclusion ? (More commercial/institutional
personal services ?)
• Less local generalised trust ? (feeling of safety and
reliability)
• Car/paid travel dependence ?
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(Concurrent) Spatial developments
Economically
• Increased specialisation of locations (regionally,
internationally)
• Increased firm size in services and production
• Increased market sizes at all scales
Urban
• Increased scales
• Lower local densities
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Spatial developments: Externalities
• Car/paid travel dependence ?
• Transport emissions (Noise, CO2, HC etc.)
• Loss of the common pedestrian environment
• Arrival of the themed pedestrian environment
• Spatial segregation (locally, regionally)
30
Jacobs (1993) 238
Urban structure: Portland, OR, circa 1860
1 Mile
31
Jacobs (1993) 221
Urban structure: Commercial Irvine, CA, circa 1980
1 Mile
32
Jacobs (1993) 222
Urban structure: Residential Irvine, CA, circa 1980
1 Mile
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Required networking tools
•
•
•
•
Car (budget for taxi)
Budget for long-distance travel
(Mobile) phone
Location-free contact point (answering service, email, website)
• Time to manage the above
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Expenditure for those tools (CH)
Share of disposable income [%]
Widmer (2001) 19
50
40
Food
30
Housing
Education & leisure
20
Transport and
communications
10
0
1840
1860
1880
1900
1920
Year
1940
1960
1980
2000
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What now ?
Transport:
• Better management of resources (demand-responsive
operation)
• Demand-responsive pricing
• Pricing of externalities
Socially:
• Better time organisation
• Common scheduling tools
• Reorganisation of working time
• Demand-responsive service delivery
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What now ?
Spatially:
•
•
•
•
Better pricing of externalities
Growth boundaries
Rescaling of the environments
Rebuilding the buildings/infrastructures of the post-war
period
• (Subsidised) local service points/local shopping facilities
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home.t-online.de/home/k-j.lebus/cdf-hgw.htm
This utopia ? (Greifswald, 1821)
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Fishman (1982)
Or this ? (Le Corbusier, 1922)
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Or that ? (Frank Lloyd Wright, 1945)
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Literature
Axhausen, K.W. (2000) Geographies of somewhere: A review of urban literature,
Urban Studies, 37 (10) 1849-1864
Congress for New Urbanism (2000) Charter of the New Urbanism: Region;
Neighborhood, District and Corridor; Block, Street and Building, McGraw Hill,
New York
Fishman, R. (1992) Urban Utopias in the Twentieth Century: Ebenezer Howard,
Frank Lloyd Wright, Le Corbusier, MIT Press, Cambridge.
Galor, O. and D.N. Weil (2000) Population, technology, and growth: From
Malthusian stagnation to the demographic transition and beyond, American
Economic Review, 90 (4) 806-828.
Gruber, A. (1998) Technology and Global Change, Cambridge University Press,
Cambridge.
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Literature
Jacobs, A.B. (1993) Great Streets, MIT Press, Cambridge.
Putnam, R.D. (1999) Bowling Alone: The collapse and revival of American
community, Schuster and Schuster, New York.
Rumley, P.A. (1984) Amenagement du territoire et utlisation du sol, Dissertation,
ORL, ETH Zürich, Zürich.
Siegenthaler, HJ. and H. Ritzmann-Blickenstorfer (eds.) (1996) Historische Statistik
der Schweiz, Chronos, Zürich
Simma, A. and K.W. Axhausen (Im Druck) Structures of commitment and mode use:
A comparison of Switzerland, Germany and Great Britain, Transport Policy.
Widmer, J.P. (2001) Ausgewählte Schweizer Zeitreihen zur Verkehrsentwicklung,
Materialien zur Vorlesung Verkehrsplanung, 1.02, IVT, ETH Zürich
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