Structural Accessibility Layer SAL Structural Accessibility Layer WU_PT1 Cecília Silva Vitor...

Structural Accessibility Layer

SALStructural Accessibility Layer

WU_PT1

Cecília SilvaVitor Oliveira, Ana Amante, Sílvia Sousa

WG2 meeting . Edinburgh UK 13 October 2011

Structural Accessibility LayerSAL – Structural Accessibility Layer

Concepts

• SAL:

– Geographical representation of comparative accessibility levels by types of transport to different types of opportunities

• Structural Accessibility:

– Assess how urban structure constrains travel choices

13 October 2011

WG2 meeting . Edinburgh UK

PeopleAccess by: different

Transport Modes

Access to:different Activities


Method

• Diversity of activities accessible

– Ex: schools, hospitals, shops, services, parks

• By transport mode:

– Non-motorized, public transport and car

• Comparison between accessibility levels by different transport modes

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2011



Indicators

• Diversity of Activity Index:

– Contour measure type

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0

1Accessibility to all the considered activities

None of the activities is accessible

fy – ponderation factor regarding frequency of use


Indicators

• Accessibility Clusters (comparative measure):

– High accessibility levels by particular transport modes

– Favourable conditions for the use of those transport modes

13 October 2011


NMPT

CAR

III

III

IV

V

VI

VII


Input

• Data:

– Statistical data (at census track)

• Population

• Employment

• Activities by type

– Geographical data

• Transport infrastructure

• Mobility system service level

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Input

• Case specific

– Study area boundaries

– Level of spatial disaggregation

– Relevant travel generating activities

• Use frequency of activities (relative importance in travel)

– Cut-off criteria and values (accessibility limits), such as:

• Time

• Cost

• Convenience, etc

– Meaning of high accessibility

• Decision vs Survey

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Output

• Accessibility levels (from 0-1) of each census track by transport mode

• Comparative accessibility:

– land use and transport conditions enabling or disabling the use of particular modes

– How urban structure constraints mode choice

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Output Examples

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Output examples

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Usefulness in practice

• Interviews with experts

– Robustness

• NMDivAct

• Clusters

– Usefulness as design support tool

– Practical applicability

– Legend: positive opinion uncertain negative opinion

no answer

Experts interviewed: 17 (transport, land use, practitioners,

researchers)13 October 2011


Structural Accessibility Layer

SALStructural Accessibility Layer

WU_PT1

Cecília SilvaVitor Oliveira, Ana Amante, Sílvia Sousa

WG2 meeting . Edinburgh UK 13 October 2011

Thank you

Structural Accessibility Layer SAL Structural Accessibility Layer WU_PT1 Cecília Silva Vitor...

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