The inaccessibility index: advantages andpotential for improving transport
planning and investment

Floridea Di Ciommo
cambiaMO | changing MObility

Content• Needs-Based vs. Utility-based approach• Relevance of needs out of paternalistic approach• Rights and Needs• Existence needs• Eliciting needs methods• Inaccessibility Index• Integration of needs approach into infrastructure projectand strategic planning. The Barcelona cases.

Needs-based vs. utility-based approach• Costs and time saving are not sufficient for evaluatingtransport projects and investments in terms of equity(Martens.& Di Ciommo 2017, Guzman et al. 2013).
• The need to carry out specific daily tasks (i.e. health,schools, food shopping, taking care of other people’smobility) have a growing impact on the evaluation of thebenefits of transport projects.

Relevance of needs
Relevant studies (Currie, 2004, Currie & Sembergs 2007,
Lucas et al. 2016, Guimarães et al. 2017, Litman 2017, Di
Ciommo et al. 2017) have shown the following:– The transport system, essential for key human needs
in terms of safety and security in health, employment
and social stability– Needs and physical, social, geographical andeconomic social exclusion.
– Observing the real needs of people is very
challenging, especially in mobility.

Rights and Needs• Needs are associated with rights:•– The basic need to have a place to live and the right tohousing;– Need to be in good health and the right to healthcare;– Need to carry out specific activities, therefore theright to mobility.
– The EU has established the right to mobility as apassengers’ right. The right to mobility per se forpotential users who need to carry out certain
essential tasks does not exist.

Existence Needs• needs are: existence needs (exercise, health, safety andsecurity, multi-tasking during travel, overcoming distancebarriers to maintain life-opportunities,• This paper is oriented to operationalize the concept of
the existence needs.
Ingvardson, J. B., Kaplan, S., Nielsen, O. A., Di Ciommo, F., de Abreu e Silva, J., & Shiftan, Y. (2017). The
Commuting Habit Loop: The Role of Satisfying Existence, Relatedness, and Growth Needs in Modal Choice (No.
17-03045).

Vía @miguelalvarez

Vía @miguelalvarez

Need-based Approach
DATA COLLECTION SUGGESTED METHODOLOGY
Goal:• Collecting data about the people´s aspirations on the extent to which theirneeds are satisfied through activity participation.
Steps:
1. Sociodemographics
2. List of frequently conducted activities
3. Eliciting needs:
1. Choice sets of 3 activities are created
2. “ Assume that on a day there is time available to conduct an activity and thatyou can choose between the following three activities”
3. “What are your considerations when choosing between the three activities?”
4. A list of needs is created
5. Grouping of closely related needs.

Need-based Approach
DATA COLLECTION SUGGESTED METHODOLOGY
4. Needs satisfaction level
Likert scale: 1 to 5
Activity 1

Activity 2

Activity 3

Activity 4

Need 1

113

5

Need 2252

4

Need 3112

1

Need 41212

Methodology
The proposed methodology includes two main steps:• Focusing on the unmet needs related to specificactivities.
• Exploring activity characteristics such as the travel time.
• The starting point is the definition of the travel time
threshold of a specific activity.

Selected geographical area: Eastern
Barcelona Metropolitan Area:• the proposed methodology implemented in lower scaleareas related to the identified centroids. 15 specificanalysis zones (AZs) have been created.

The data preparation includes six steps:• Selecting the mobility survey data on people living insidea specific area
• Making a preliminary analysis of the new sample,
including inhabitants• Regrouping the filtered data by typology of trip: people
with the same trip purpose, transport mode and lengthof trip were included in the same typology (Di Ciommoet al. 2016).

Methodological steps•Defining a given time threshold for each of thecategories in the above typology•Highlighting the typologies of more problematic trips.
•Finding groups of population that seem to experience
less satisfaction when it comes to meeting their needs.

Identified Time Threshold TT
Trip typology
CER04_CER06_
2_3_2
MON01_MON0
2_1_1_1
BES02_COL03_
4_2_3
COL02_BES01_
6_3_2

TT
AverageTTModeTTMedian18,5151510,161010323025282525Legend:
Each code (i.e. CER04_CER06_2_3_2 includes:
origin_destination_purpose_mode_length
1) Origen and destination use the code of identified Azs
2) Purposes refer to work=1, study=2, daily shopping=3, occasional
shopping=4, medical=5, visit=63) Modes of transport refer to NMT=1, PUBLIC=2, PRIVAT=34) Length: 0-5 km=1, 6-15 km=2, 16-25km=3, etc.

Selection of people groups in needs• Users’ level of satisfaction is defined as follows:• High satisfaction for likert points between 10-8
• Medium satisfaction for likert points between 7-4• Low satisfaction for likert points between 3-0
Satisfaction/TT Low 0-3
Above TTX
Below TT?

Medium 4-7 High 10-8?
?
?
?

Identification of needs in transport
through the inaccessibility index
Unmet needssocial exclusion

Lower satisfaction with acharacteristic of the needed
activity (i.e. travel time)

Inaccessibility to essential activities

Eliciting people’s needs

Inaccessibility index
𝐣𝐣𝒎𝒎,𝒑𝒑,𝒍𝒍𝒎𝒎,𝒑𝒑,𝒍𝒍∑𝐧𝐧
𝐝𝐝=𝟏𝟏 𝑻𝑻𝑻𝑻𝒐𝒐,𝒅𝒅 ∗∑𝐢𝐢=𝟏𝟏 𝑵𝑵𝑵𝑵𝒐𝒐,𝒅𝒅
𝑚𝑚 ,𝑝𝑝,𝑙𝑙
𝐼𝐼𝐼𝐼𝑜𝑜,𝑑𝑑 = 1 −𝐠𝐠
𝒎𝒎,𝒑𝒑,𝒍𝒍∑𝑵𝑵𝑵𝑵
𝐢𝐢=𝟏𝟏𝒐𝒐,𝒅𝒅

where:
m represents the transport mode; p the trip purpose; l the length; othe trip origin and d the trip destination.
TT is the time threshold defined for a given trip typology; it is equal
to 1 if the travel time is less or equal than the time threshold. Otherwise itis 0.
NU is the number of users making a given trip.
n is the number of the considered typologies.
j is the number of users which are realizing the same trip and that aresatisfiedg includes the number of both groups of satisfied and unsatisfied
users, that are carrying out the same typology of trip

Feminization of Mobility

Vía @miguelalvarez, @CollectiuPunt6

Urban area of tramway extension:Sant’Adriá-Badalona portBuffers for eliciting tramway information

The IA index contribution to the BMA
strategic plan for decreasing poverty
Identified poverty corridors: a BRT proposal

Estimation of the IA index for revealing
people’s needs
Estimation of the IA index for revealing people’s needs/
Public transport accessibility through the supply sideResults and Conclusions• Identification of population groups to whom transport
policy should be mainly addressed so as to increasetransport equity• The opportunity of reaching activities in given areas isrepresented by time thresholds, transport networks
location and the users' level of satisfaction regarding
unmet needs.

Results for the low-income part of BMA• 1. Policy makers should invest a greater effort inwinning over vulnerable groups of the population whorevealed their unmet needs.
• 2. The network effect that is to the detriment of lowincome social groups when they face a sparse public railtransport network• The inclusion of the inaccessibility index provides a way
to consider equity in a non-paternalistic approach

Thanks
Discussion

Floridea Di Ciommo, chair of TRB Behavioral processes committee, member of thecommittee Women issues in transportation.
cambiaMO
floridea.diciommo@cambiamo.net