from time gains to land use: the new challenges of...

From time gains to land use: the

new challenges of accessibility

modelling

Pr. Yves Crozet Laboratory of Transport Economics (LET)

University of Lyon (IEP) - France

[email protected]

www.let.fr

MOEBIUS Project – Final conference

Luxembourg – 23 10 2013

Introduction

• “Accessibility at point 1 to a particular type of

activity at point 2 is directly proportional to

the size of the activity at point 2 and inversely

proportional to a function of the distance

separating the two points.

• The total accessibility at point 1 to the activity

is the summation of the accessibility to each of

the points around point 1” (Hansen 1959, p.

74 ff)“

Urban mobility: some new trends

• Some paradoxical changes in urban mobility policies

• The decreasing relevancy of Cost Benefit Analysis (CBA) to define public choice

• A public preference for slow modes (tramway, bus, bikes, pedestrian streets..)

• Voluntary restrictions to car mobility (lower speed, reduced width of roads…)

• Towards a lower accessibility ? A risk for urban attractiveness?

The key ratio

• A city is a place where the number of opportunities

is higher than in other places

• Travel cost (time + money) is compared to the

corresponding amenities

• What we have to take into account is the ratio

Opportunities ____________________

Travel cost

Time gains versus land use:

what is at stake?

Objective function of

the decision maker ?

Decision-maker?

Speed and time

gains

Land use and

environment

Benevolent and

all-knowing ruler

Ignorant or

opportunist

decision maker


what is at stake? Objective function

of the decision

maker ?

Decision-maker?

Speed and

time gains

Land use and

environment

Benevolent

and all-

knowing ruler

Accessibility

in CBA,

transport

demand and

traffic growth

Ignorant or

opportunist

decision

maker

• We can describe accessibility as a function of

territorial structure and transport supply.

• with

• Ai = Accessibility to destinations D from point i

• Dj = Activity destinations at points j

• cij = Generalized cost (time, price…)

)( ij

j

ji cfDA

Time gains and accessibility

• The first age of accessibility is dominated by the

search of speed and especially road speed for cars.

• In this age, speed is the main factor of the

improvement of urban accessibility.

• The dream of policy makers is the same than the

dream of car drivers: to keep car accessibility

during peak hours at the same level than during off

peak hours.


what is at stake?



Decision-maker?

Speed and time

gains

Land use and

environment

Benevolent and all-

knowing ruler

Accessibility in

CBA, transport

demand and traffic

growth

Ignorant or

opportunist

decision maker

Cost efficiency

analysis of

accessibility gains

« social effective

speed”

10

« SNIT = National Scheme

for Transport Infrastructures»

Tours-Bordeaux

Public Subsidies = 5 euros/passenger

during 50 years

Marseille-Nice

Public subsidies=

35 euros/pass

during 30 years.

Social effective speed

= 15 km/h

Energy and Equity (Ivan Illich

and J.P. Dupuy 1973)

• The more you increase speed, the

more you reduce equity

• From the generalized cost to the

generalized speed or « effective

speed »

• Ef. Speed = 1 / (1/S) + (k/w))

« Effective Speed » and

« Social Effective Speed » • Average speed = harmonic

average

n/ [(1/V1)+(1/V2)]

• Effective speed of bike

• 1/ [(1/V)+(k/W)]

• 1/ [(1/14)+ (0.001/8) =

13.9

• Supersonic effective speed

• 1/ [(1/2000)+ (1/6)] =

6km/h

• High speed rail effective

speed

1/ [(1/200)+ (0.15/8)] =

40km/h

• High speed rail social

effective speed

• 1/ [(1/200)+ (0.5/8)] =

14.8km/h

• Regional train

• 1/ [(1/100)+ (0.30/8)] =

21km/h

Tramways in Paris Region within 2020


what is at stake?



Decision-maker?

Speed and time

gains

Land use and

environment

Benevolent and all-

knowing ruler

Accessibility in

CBA, transport

demand and traffic

growth

Accessibility index

and map-based

tools

Ignorant or

opportunist

decision maker

Cost efficiency

analysis of

accessibility gains

« social effective

speed”

The perverse effects of speed on

land use

• A second age of accessibility emerges when road congestion is recurrent during peak hours.

• Public transit (PT) becomes the priority to keep or to improve urban accessibility.

• Speed is therefore less important than reliability, frequency and comfort of PT.

• Even some relatively slow modes (walking, cycling) are promoted.

• Decision makers have a preference for density

ijcβ

j

ji DA

exp

« Attractive Masses »

Housing

Jobs Shops, Leisure

Generalized cost

Monetary cost +

Travel Time +

parameters

Parameter

Sensitivity to Generalised cost

Economic theory of urban accessibility

Hansen 1959, Koenig 1974

MOSART : an innovative

modelling platform for planning

sustainable mobility

MOSART (MOdeling and Simulating

Accessibility to netwoRks and Territories)

• Orthophotos

A GIS TO MODEL ACCESSIBILITY (MOSART)

• Census data

• Administratives areas

•Road network

•PT network

• Shops et services

MOSART Version 2 : case study

Density and new apartments per municipality(1991)

Sources : SITADEL, INSEE

Density and new apartments per municipality (2007)

Sources : SITADEL, INSEE


what is at stake?



Decision-maker?

Speed and time

gains

Land use and

environment

Benevolent and all-

knowing ruler

Accessibility in

CBA, transport

demand and traffic

growth

Accessibility index

and map-based

tools

Ignorant or

opportunist

decision maker

Cost efficiency

analysis, cost of

accessibility gains,

« social effective

speed”

Accessibility maps

to open the black

box of transport

demand modelling

Road congestion during morning peak hours

Road congestion with the new

infrastructure during morning peak

hours

32

Accessibility change with the new

infrastructure

Accessibility gains

33

Accessibility change with the new

infrastructure

Accessibility gains

Accessibility gains to jobs

outside from Grand-Lyon

Road traffic in Paris 1953 and

1969

Conclusion

• The coming challenge of urban mobility is:

how public policies on land-use and

transport supply can help to keep an

acceptable level of accessibility in a context

of rising travel costs?

• From “How accessibility shapes land use”

(Hansen 1959)

• To “How land use and environment

priorities shape accessibility policies”

Conclusion (2)

• Tell me what accessibility you are ready to

promote, and how (mode ? speed ?

reliablity? density?) and for who ?

• Tell we what accessibility you are ready not

to promote, and even to reduce…

• And I’ll tell you what city you prepare for

tomorrow!

j

ijjicDA βexp

Some references • Hansen, W.G. (1959) ‘How accessibility shapes land-use’, Journal of the American

Institute of Planners, 25, pp. 73-76

• Johannsson, B., Klaesson, J., Olsson M. (2002) ‘Time distance and labour market

integration’, Papers in Regional Science, 81-3, pp. 305-327

• Koenig, J.G. (1974) ‘Théorie économique de l'accessibilité urbaine’, Revue

Economique, XXV-2, pp. 275-297

• Morris, J.M., Dumble, P.L. and Wigan, M.R. (1979), ‘Accessibility indicators for

transport planning’, Transportation Research-A, 13A, pp. 91-109

• Pirie, G.H. (1979), ‘Measuring accessibility : a review and proposal’, Environment and

Planning A, 11, pp. 299-312

• Raux, C., Souche S. (2004) ‘The acceptability of urban road pricing. A theoretical

analysis applied to experience in Lyon’, Journal of Transport Economics and Policy, 38,

Part 2, pp 191-216

• Stalinov, K. (2003) ‘Accessibility and Land Use : The Case of Suburban Seattle, 1960-

1990’, Regional Studies, 37.8, pp. 783-794

D

prix

coût

déplacements entre

zones i et j

A

O

surplus initial

T2

c2

d2

mimmi tvotcCg

2

1

ij

ij

c

c

ijijdcTS

T1

c1d1

Car speed and consumption of

space-time –(m2/h)

m2

Speed km/h

• Demand Curve ?

Wilson (1970)

k

ikk

ijj

iijcfD

cfDOT

)(

)(

k

ikki cDA exp

ijij ccf exp)(

• Accessibility

(Hansen, 1959)

• Surplus change for

zone i jzones

c

c

ijiji

ij

ij

dcTS

2

1

12

1

2

lnlnexp

exp

ln iii

j

ijj

j

ijj

ii AA

O

cD

cDO

S

• Neuburger (1971)

= Koenig (1974)

ijcβ

j

ji DA

exp

« Attractive Masses »

Housing

Jobs Shops, Leisure

Generalised cost

Monetary cost +

Travel Time +

parameters

Parameter

Sensitivity to Generalised cost

Economic theory of urban accessibility

Hansen 1959, Koenig 1974

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