urban spatial structure and mobility by orm

8/3/2019 Urban Spatial Structure and Mobility by ORM

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Urban Spatial Structure and Mobility

Outline :

A. Transportation and Urban Form

B. Urban Land Use and Transportation

C. Urban Mobility

D. Urban Transport Problems



A – Transportation and Urban Form

■ 1. Elements of the Urban Form■ 2. Evolution of Transportation and Urban Form

■ 3. The Spatial Imprint of Urban Transportation

■ 4. Transportation and the Urban Structure



1. Elements of the Urban Form

■ Urbanization• Dominant trend of economic and social change.

• Especially in the developing world.

• Growing size of cities.

• Increasing proportion of the urbanized population:• More than doubled since 1950.

• Nearly 3 billion in 2000, about 47% of the global population.

• 50 million urbanites each year, roughly a million a week.

• By 2050, 6.2 billion people, about two thirds of humanity, will be urban

residents.• Due to demographic growth and rural to urban migration.

■ Urban mobility issues• Increased proportionally with urbanization.




■ Urban transportation• Requirements of collective, individual and freight transportation.

• Composed of modes, infrastructures and users.

• Urban transport modes:

• May complementary to one another or competing.• Transit is a urban form of transportation (high ridership and short

distances).

• Urban transport infrastructures:• Physical form used by modes.

• Consume space and structure the city.• Urban transport users:

• Wide variety of socioeconomic conditions.

• Variety of spatial conditions.

• Urban transport as a choice or a constraint.



Transportation and Urban Form

Transportation

Modes

Infrastructures

Users

Urban Form

S p a t i

al

i m pr i n t




■ Collective Transportation (public transit)• Provide publicly accessible mobility over specific parts of a city.

• Benefiting from economies of scale.

• Tramways, buses, trains, subways and ferryboats.

■ Individual Transportation• Includes the car, walking, cycling and the motorcycle.

• People walk to satisfy their basic mobility.

■ Freight Transportation

• Cities are dominant production and consumption centers.• Activities are accompanied by large movements of freight.

• Delivery trucks converging to industries, warehouses and retail

activities.

• Major terminals.




■ Density issues• Modern cities:

• Inherited an urban form created in the past.

• Can be monocentric or polycentric (more common).

• Movements are organized or disorganized.

• European, Japanese and Chinese:• Tend to be monocentric.

• Movements tend to be organized.

• 30 to 60% of all trips by walking and cycling.

•

Australian and American cities:• Built recently and encourages automobile dependency.

• Tend to be polycentric.

• Movements tend to be disorganized.



Possible Urban Movement Patterns

Monocentric Polycentric

Or g ani z e d

D i s o

r g ani z e d



2. Evolution of Transportation and Urban Form

■ Evolution of transportation• Led to a change in most urban forms.

• New central areas expressing new urban activities (suburbs).

• Central business district (CBD):

• Once the primary destination of commuters and serviced by publictransportation.

• Challenged by changing manufacturing, retailing and management

practices.

• Emergence of sub-centers in the periphery.

•

Manufacturing:• Traditional manufacturing depended on centralized workplaces and

transportation.

• Technology has rendered modern industry more flexible.



One Hour Commuting According to Different Urban

Transportation Modes

Streetcar line

Freeway

Walking

Streetcar

Cycling

Automobile

Automobile with

freeways

10 km



A B C

Core activities

Central activities

Peripheral activities

Evolution of the Spatial Structure of a City

Central area

Major transport axis




■ Contemporary changes• Dispersed urban land development patterns:

• Abundant land, low transportation costs, tertiary industries.

• Strong relationship between urban density and car use.

• Faster growth rate of built areas than population growth.

• Decentralization of activities:• Commuter journeys have remained relatively similar in duration.

• Commuting tends to be longer and made by privately owned cars rather

than by public transportation.

• Most transit and road systems were developed to facilitate suburb-to-city,

rather than suburb-to-suburb, commuting.

• Suburban highways are often as congested as urban highways.




■ Constance in commuting time• Most people travel less than 30 minutes in order to get to work.

• People are spending about 1.2 hours per day commuting.

• Different transport technologies are associated with different

travel speeds and capacity.• Cities that rely primarily on non-motorized transport tend to be

different than auto-dependent cities.

• United States:• Lowest average commuting time in the world, around 25 minutes in 1990.



Average Journey to Work Travel Time, 1990

0

510

15

20

2530

35

40

United States Western Europe Japan Other Asia Australia

M i n u t e s



3. The Spatial Imprint of Urban Transportation

■ Land for transportation• Pre-automobile era:

• About 10% of the land of a city was devoted to transportation.

• A growing share of urban areas is allocated to circulation.

•

Variations of the spatial imprint of urban transportation:• Between different cities.

• Between different parts of a city (central and peripheral areas).

• Private car:• Requires space to move around (roads).

• Spends 98% of its existence stationary in a parking space.• Consumes a significant amount of urban space.

• 10% of the arable land of the United States allocated for the car.




■ Components of the spatial imprint of urban transportation• Pedestrian areas:

• Amount of space devoted to walking.

• Space is often shared with roads as sidewalks may use between 10%

and 20% of a road's right of way.

• In central areas, pedestrian areas tend to use a greater share of the right

of way (whole areas may be reserved only for pedestrians).

• Most of pedestrian areas are servicing access to parked automobiles.

• Roads and parking areas:• Amount of space devoted to road transportation, which has two states of

activity; moving or parked

• On average 30% of the urban surface is devoted to roads.

• Another 20% is required for off-street parking

• For each car there is about 2 off-street and 2 on-street parking spaces.

• Roads and parking lots: between 30 to 60% of the total urban surface.



Land Area Consumed by the Car in Selected Countries,

1999

0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5%

United States

Canada

Mexico

Japan

France

Germany

United Kingdom

Sweden

0 100 200 300 400 500 600 700 800

% of total land area used by the car

Area per capita (sqr. meters)



Urban Spatial Structure, Hempstead, Long Island, New York

Road (11.9%)

Parking (21.8%)Building (5.3%)

Other (61.0%)




• Cycling areas:• In a disorganized form, cycling simply share access to road space.

• Many attempts to create a space specific to the circulation of bicycles in

urban areas, namely with reserved lanes and parking facilities.

• Transit systems:• Many transit systems, such as buses and tramways, are sharing road

areas, which often impairs their efficiency.

• Subways and rail have their own infrastructures and their own areas.

• Creation of road lanes reserved to buses.

• Transport terminals:

• Amount of space devoted to terminal facilities such as ports, airports,railyards and distribution centers.

• Globalization increased the amount of people and freight circulation and

the amount of urban space required to support those activities.

• Many major terminals are located in the peripheral areas of cities, which

are the only locations where sufficient amounts of land is available.



Pedestrian, Cycling and Road Spaces, Amsterdam, Netherlands



Road Highway Activity center Transit lineI II

III IV



4. Transportation and the Urban Structure

■ Type I - Completely Motorized Network• Car-dependent city with a limited centrality:

• Massive network of high capacity highways.

• Large parking lots.

• Low to average land use densities.

• Public transit is having a residual function.

• Relationship between commercial / industrial / residential space

and parking space.

• Secondary road converges at highways, along which small

centers are located, notably nearby interchanges.• Examples:

• Cities where urban growth occurred in the second half of the twentieth

century:

• Los Angeles, Phoenix, Denver and Dallas.




■ Type II - Weak Center • Average land use densities and a concentric pattern.

• CBD offers slightly more jobs than it is possible to move by car.

• Under-used public transit system:

• Unprofitable in most instances and thus requires subsidies.• Impossible to serve all the territory with the transit system.

• Ring roads:• Emergence a set of small centers in the periphery.

• Convergence of radial lines, some of them effectively competing with the

downtown area for the location of economic activities.• Examples:

• Older cities that emerged if the first half of the twentieth century:

• Melbourne, San Francisco, Boston, Chicago and Montreal.




■ Type III - Strong Center • High land use density:

• High levels of accessibility to urban transit.

• Limited needs for highways and parking space in the central area.

•

High capacity and efficient public transit servicing most of themobility needs.

• Convergence of radial roads and ring roads:• Location of secondary centers, where activities that could no longer able

to afford a central location have located.

•Examples:

• Cities having important commercial and financial function.

• Growth in the late 18th century.

• Paris, New York, Shanghai, Toronto, Sydney and Hamburg.




■ Type IV - Traffic Limitation• Average-sized cities having a high land use density that were

planned to limit the usage of the car in central zones.

• Limited driving and parking spaces are available.

•“Funnel effect“:

• Public transit is used in the central area.

• Individual transportation takes a greater importance in the periphery.

• Keeps cars from the central areas while giving mobility in the suburbs.

• Examples:

• Cities having a long planning history aiming to provide mobility by publictransit.

• Historical downtown area protected from heavy circulation.

• London, Singapore, Hong Kong, Vienna and Stockholm.



The Rationale of a Ring Road

SecondaryCenter

CityCenter

Avoiding the congested

central area

Structuring

Suburban

development

Spatial Structure Accessibility

510

105

5

10

10

5

A B

A to B = 30

A B510

105

5

10

10

510 10

1010

A to B = 20



B – Urban Land Use and Transportation

■ 1. The Land Use - Transport System■ 2. Urban Land Use Models



1. The Land Use - Transport System

■ Urban land use• Nature and level of spatial accumulation of activities.

• Human activities imply a multitude of functions:• Production, consumption and distribution.

•

Activity system:• Locations and spatial accumulation form land uses.

• The behavioral patterns of individuals, institutions and firms will

have an imprint on land use.

■ Land use relationships• Land use implies a set of relationships with other land uses.

• Commercial land use:• Relationships with its supplier and customers.

• Relationships with suppliers: related with movements of freight.

• Relationships with customers: movements of passengers.



Land UseTransport System Spatial Interactions

• Accessibility•

Traffic assignmentmodels• Transport capacity

• Economic base

theory• Location theory

• Traffic generationand attraction models

• Spatial interaction

models• Distance decay

parameters• Modal split

Infrastructures(supply)

Friction of SpaceSpatial Accumulation

(demand)

The Transport / Land Use System



2. Urban Land Use Models

■ Concentric paradigm• Land use of function of distance from a nucleus.

■ Sector and nuclei paradigm• Influences of transport axis and several nuclei on land use.

■ Hybrid paradigm• Try to integrate the strengths of each representation.

■ Land rent paradigm• Land use as a market where different urban activities are

competing for land usage at a location.



IV - Working class zone

V - Residential zone

VI - Commuter zone

I - Loop (downtown)

II - Factory zone

III - Zone of transition

LOOP

BungalowSection

Residential District

Ghetto

Two Plan

Area

Model Chicago, 1920s

B l a c k B e l t

Burgess’ Urban Land Use Model



2

3

4

4

5

3

3

1

3

3

3

1 CBD2 Wholesale and light manufacturing3 Low-class residential4 Middle-class residential5 High-class residential

12

3

45

3

3

6

7

89

6 Heavy manufacturing7 Sub business district8 Residential suburb9 Industrial suburb

Sector Nuclei

Sector and Nuclei Urban Land Use Models

2



Hybrid Land Use Model

CenterIndustrial / ManufacturingCommercial

ResidentialTransport axis



Rent

Distance

A- RetailingB- Industry/

commercial

C - Apartments D - Single houses

1 –

Bid rent curves

Land Rent and Land Use

2 –

Overlayof bid rentcurves

C i t y l i mi t s

urban spatial structure and mobility by orm

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