Table Of ContentPerformance and Design of Taxi Services at Airport
Passenger Terminals
David Carvalho Teixeira da Costa
Dissertação para obtenção do Grau de Mestre em
Sistemas Complexos de Infraestruturas de Transportes
(CTIS)
Júri
Presidente: Prof. Dr. José Manuel Viegas
Coordenador: Prof. Dr. Richard de Neufville
Co-coordenador: Prof. Dr. Rosário Macário
Vogal: Prof. Dr. João Claro
Outubro, 2009
Acknowledgements
Throughout this academic adventure, there were many times when I wondered on the actual
relevance of the result of my work or my ability to finish it. It‟s only normal to lose faith at certain
moments during the writing of a thesis, but I never lost mine, fortunately. Self-motivation is a key
instrument for researchers who are forced to semi-isolate themselves and dive into the complex work
they perform, and I‟ve learned that very well. Although one should always try to think ahead,
regardless of the difficulties, it was not always easy to identify that line of thought that eventually
drives your work to success, and the help of our supervisors is like a light in the dark. Their role in this
process was fundamental, not only to guide and keep motivation running, but also to teach, and most
certainly to learn as well.
I‟d like to thank Professor Richard de Neufville for his rich and enlightening coordination, his
unyielding patience and his faith on my capacity to actually work with him on this topic. For me, it was
an honor to work with such a brilliant academic mind and to be able to tap into several hidden truths of
engineering. Through his classes, through his coordination and teachings and through his own unique
perspective, I have surely become a better engineer, better prepared for my professional life. I‟d also
like to thank Professor Rosario Macário, which has co-supervised my thesis and has always been
there whenever I needed closer guidance on several issues, especially regarding the regulation and
institutional parts.
This work implied a substantial effort to plan and execute data gathering initiatives. For several
days, I had to travel to the airport and spend some hours observing how queues behaved. For this I
needed help and help I got. Teixeira‟s help in this phase was magnificent and I thank him for the
courage, friendship and sacrifice of standing by my side at the airport, in the middle of August, during
almost a full day. In an environment where the observed people did not like to be observed, a
significant effort had to be made to disguise my presence. Unfortunately, this was not always easy - a
very rich experiment for me. Also, I‟d like to thank Mauro, my tireless friend and colleague, who has
spent the last year fighting for the same objectives as myself. For all the sleepless nights spent at IST,
for all the obstacles we‟ve overcome…we make a great team and you know I admire you!
To all my friends and family, my ex-colleagues at Engimind and Lisbon Municipality and my
professors at CTIS, my huge thank you. Couldn‟t have done it without you!
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Abstract
The main objective of this dissertation is to analyze, through the consideration of a case-study -
Portela Airport - the current operational and regulatory design options in systems of taxi service
provision at airport passenger buildings, and propose, based on its performance levels, alternative
schemes and possible interventions that can improve the existing services.
On the regulatory side, the methodology chosen to pursue these objectives was based on the
systematic analysis of the involved stakeholders, their institutional roles and power-sharing
mechanisms. On the operational side, an extensive data collection effort was performed and used to
calibrate a simulation model which represents system behavior. Both of these analyses were then
subject to a scenario-building process, in order to test different stimulus for both perspectives.
As main conclusions, it must be stated that the current taxi service system at Terminal 1 is not
able to adequately cope with peak-hour solicitations and offer good quality of service to passengers at
these times. Queues are a fundamental part of the problem and their behavior must not be diluted in
average-based analysis that do not expose the frailties of the system at peak-hours, some of them
intensified by seemingly small exogenous factors such as police coordination or taxi maneuvering
needs. They may also be a key part of the solution, as slight physical rearrangement of queues or
service areas can lead to greatly improved service as regards queue length, delays and reliability.
ANA and Lisbon Municipality should thus behave proactively to face this problem.
Key Words:
Taxi Services
Queuing Systems
Airports
Regulation
Simulation
Simul8
3
Resumo
O objectivo desta dissertação é analizar, através da consideração dum caso de estudo –
Aeroporto da Portela – as actuais opções de design operacional e regulatório em sistemas de táxi em
Terminais de Aeroportos, e propor, baseado nos níveis de performance, esquemas alternativos e
possíveis intervenções que permitam melhorar os serviços existentes.
Do lado regulatório, a metodologia escolhida para alcançar estes objectivos foi baseada na análise
sistemática dos stakeholders, seus papeis institucionais e mecanismos de partilha de poder. Do lado
operacional, um esforço extensivo de recolha de dados foi efectuado e usado para calibrar um
modelo de simulação que representa o comportamento sistémico. Ambas as análises foram sujeitas a
um processo de construção de cenários, de forma a testar diferentes estímulos.
Como principais conclusões, sublinha-se que o actual serviço de táxis no Terminal 1 não é capaz
de adequadamente lidar com solicitações de período de ponta e oferecer boa qualidade de serviço
aos passageiros. As filas de espera são parte fundamental do problema e o seu comportamento não
deve ser diluído em análises baseadas em médias que não expõem as fragilidades do sistema nos
períodos de ponta, intensificadas por factores aparentemente pequenos e exógenos como
coordenação policial ou necessidade de manobras dos taxis. As filas de espera podem ser parte da
solução, já que ligeiras reorganizações destas ou das áreas de serviço podem levar a grandes
melhorias no que toca à sua dimensão, tempos de espera e fiabilidade. A ANA e o Município de
Lisboa devem comportar-se proactivamente para enfrentar este problema.
Palavras-chave:
Serviços de Táxi
Sistemas de Filas de Espera
Aeroportos
Regulação
Simulação
Simul8
4
Table of Contents
Acknowledgements ............................................................................................................. 2
Abstract ............................................................................................................................... 3
Resumo ................................................................................................................................ 4
Table of Contents ................................................................................................................ 5
Table of Figures ................................................................................................................... 7
Acronyms ............................................................................................................................. 9
Chapter 1 – Introduction ....................................................................................................10
1.1. Objectives and motivation .........................................................................................10
1.2. Thesis Structure ........................................................................................................11
1.3. State of the Art ..........................................................................................................12
1.3.1. Sector Framework ...........................................................................................12
1.3.2. Literature Review ............................................................................................14
1.3.2.1. Regulation ................................................................................................14
1.3.2.2. Modeling, Queuing Theory and Simulation ...............................................16
Chapter 2 – Problem definition and methodology ...........................................................22
2.1. Regulatory and Institutional Issues............................................................................22
2.1.1. Problem definition ...........................................................................................22
2.1.2. Methodology ...................................................................................................24
2.2. Operational Issues ....................................................................................................26
2.2.1. Problem definition ...........................................................................................26
2.2.2. Methodology ...................................................................................................28
2.2.3. Field Data Collection Plan ...............................................................................30
Chapter 3 – Case Study – Portela Airport .........................................................................36
3.1. General background .................................................................................................36
3.1.1. Introduction .....................................................................................................36
3.1.2. The airport .......................................................................................................37
3.2. Analysis of the Taxi Service at Terminal 1 .................................................................40
3.2.1. Regulatory and Institutional Context ................................................................40
3.2.1.1. General Market Characteristics ................................................................41
3.2.1.2. General Licensing ....................................................................................42
3.2.1.3. Regulation ................................................................................................44
3.2.1.4. Main Stakeholders and bargaining power.................................................45
3.2.1.5. Institutional framework .............................................................................49
3.2.1.6. Overview summary ..................................................................................50
3.2.2. Operational Context ........................................................................................53
3.2.2.1. Spatial description of the system ..............................................................54
5
3.2.2.2. Analysis of the Collected Data ..................................................................58
3.2.2.3. Simulation Model ......................................................................................67
3.3. Scenario Building ......................................................................................................75
3.3.1. Regulatory and Institutional Policy Actions ......................................................75
3.3.1.1. Policy Actions Analysis .............................................................................75
3.3.1.2. Policy Actions Evaluation .........................................................................78
3.3.2. Operational Scenarios .....................................................................................80
3.3.2.1. Scenario Analysis .....................................................................................80
3.3.2.2. Scenario Evaluation .................................................................................86
Chapter 4 – Conclusions and Proposals ..........................................................................88
4.1. Main Conclusions ......................................................................................................88
4.1.1. Regulations and Institutional Framework .........................................................89
4.1.2. Operational Framework ...................................................................................91
4.2. Intervention Proposals and Suggestions for Future Research ...................................94
Bibliography .......................................................................................................................96
Web Sites ............................................................................................................................98
Annexes ..............................................................................................................................99
I. Literature Review .................................................................................................... 100
II. Field Data ............................................................................................................... 107
III. Distribution Fitting - Inter-arrival and Service Times ................................................ 117
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Table of Figures
Figure 1 – Two examples of Private Service Paratransit services, adapted from (Cervero, 1992) ...... 14
Figure 2 - Expected delay for four different levels of service capacity at an Airport: R1= capacity is 80
movements per hour; R2 = 90; R3 = 100; R4 = 110 (Odoni, 2007) ...................................................... 18
Figure 3 - Delay versus Utilization ratio (ρ) and confidence limits evolution (left) and Dependence on
Variability (Variance) of Inter-Arrival Times and of Service Times (right), adapted from (Odoni, 2007)19
Figure 4 – Graphical representation of cumulative arrivals and departures from a queue (Newell, 1982)
............................................................................................................................................................... 20
Figure 5 – Graphical representation of departure times (Newell, 1982) ............................................... 21
Figure 6 – General Institutional Framework of Airport Taxi Services .................................................... 23
Figure 7 – Components of a Basic Queuing Process at an Airport Taxi Stand .................................... 27
Figure 8 – Passengers Traffic by Month (Source: Annual Traffic Report – ANA, 2008) ....................... 30
Figure 9 – Passenger Traffic by Day of the Week (Source: Annual Traffic Report – ANA, 2008) ........ 31
Figure 10 – Arriving Passengers during the Easter Holidays week in 2006 (Source: ANA, 2006) ....... 31
Figure 11 – Hourly distribution of Passengers and Taxis at the Airport Arrivals taxi stand (Source:
ANA, 2006) ............................................................................................................................................ 31
Figure 12 – Sample Size parameters for the Service Times and Inter-Arrival Times for Groups ......... 34
Figure 13 – Data Collection Scheme ..................................................................................................... 34
Figure 14 – Terminal 2 location (Source: Virtual Earth) ........................................................................ 38
Figure 15 – Blueprints of the future New Lisbon Airport at Alcochete (Source: www.naer.pt) ............. 38
Figure 16 – Three of the main Tourism destinations from Portela Airport (marker A), in the Lisbon
Metropolitan Area, upper left: Chiado, upper right: Belém, bottom: Cascais (Source: Google Maps).. 39
Figure 17 – Institutional framework regarding Portela‟s taxi service system ........................................ 50
Figure 18 - Schematic classification of taxicab regulatory systems (Schaller, 2007) – Lisbon case, in
blue ........................................................................................................................................................ 51
Figure 19 – Lisbon Airport - Terminal 1 (Source: Google Earth) ........................................................... 55
Figure 20 – Taxi Service Organization at the Arrivals of Terminal 1 ..................................................... 56
Figure 21 – System configuration at the Arrivals Taxi Stand ................................................................ 57
Figure 22 – Histogram for Inter-Arrival Times for Groups ..................................................................... 59
Figure 23 – Histogram for Group Size ................................................................................................... 59
Figure 24 – Comparison between Group Size Proportions from the different measurements ............. 60
Figure 25 – Histograms for Service Times ............................................................................................ 61
Figure 26 – Service Time averages and standard deviations ............................................................... 61
Figure 27 – Main conflicts that can justify delays and differences in service time distributions ............ 63
Figure 28 – Arrival Curve and Exit Curve based on the collected data ................................................ 64
Figure 29 – Queue Length evolution ..................................................................................................... 65
Figure 30 – In-Queue Waiting Time evolution ....................................................................................... 65
Figure 31 – Main results for Queue Length, In-Queue Waiting Time and Arrival/Service Ratio ........... 66
7
Figure 32 – Final System Configuration for the current situation at Portela‟s Arrivals Taxi Stand ....... 70
Figure 33 – Final result comparison between the Empirical Process and the Simulation Model ......... 73
Figure 34 – Queue Evolution for the Empirical (above) and Simulation (below) Methods ................... 74
Figure 35 – SWOT analysis for Policy Action I – Introduction of Taxi Sharing ..................................... 79
Figure 36 - SWOT analysis for Policy Action II – Introduction of a Special Airport Fleet and Concession
changes ................................................................................................................................................. 79
Figure 37 - SWOT analysis for Policy Action III - Market segmentation and other changes to the
Departures Taxi Stand ........................................................................................................................... 79
Figure 38 – System configuration for Scenario I – Extra Service Lane, 2 extra servers....................... 80
Figure 39 – Main SIMUL8 results for the Scenario I system configuration ........................................... 81
Figure 40 - System configuration for Scenario II – One service lane, multiple servers ........................ 82
Figure 41 – Main SIMUL8 results for the Scenario II system configurations ........................................ 83
Figure 42 - System configuration for Scenario III – 2 queues, Special Service Type ........................... 84
Figure 43 - Main SIMUL8 results for the Scenario III system configuration .......................................... 85
Figure 44 – Results for the main Queue Size indicators ....................................................................... 86
Figure 45 – Results for the main Queuing Time indicators ................................................................... 86
Figure 46 - Schematic classification of taxicab regulatory systems (Schaller, 2007) ......................... 101
Figure 47 - Key characteristics of entry-related policies - adapted from (Schaller, 2007) .................. 102
Figure 48 – Customer Wait Time versus Number of Taxis (Li, 2006) ................................................. 105
Figure 49 – Mean customer demand by time of the day (Curry, 1977) .............................................. 106
Figure 50 – Collected Inter-Arrival Times ............................................................................................ 114
Figure 51 – Collected Service Times .................................................................................................. 116
Figure 52 – Exponential Theoretical Distribution fitting to the Inter-Arrival Times experimental
distribution ........................................................................................................................................... 117
Figure 53 – Goodness of fit and descriptive statistics summary for the Inter-Arrival Times .............. 117
Figure 54 – Lognormal theoretical distribution fitting to the Service Times experimental distribution 118
Figure 55 - Goodness of fit summary and descriptive statistics for the Service Times....................... 118
Figure 56 - Lognormal theoretical distribution fitting to the Service Times experimental distribution
(Scenario II) ......................................................................................................................................... 119
Figure 57 - Goodness of fit summary and descriptive statistics for the Service Times (Scenario II) .. 119
8
Acronyms
ASAE - Food and Economic Safety Authority
ANA - Aeroportos e Navegação Aérea
ATL - Lisbon Tourism Association
CAA - Civil Aviation Authority
CAP - Professional Aptitude Certificate
DECO - Consumer's Defense Association
FIFO - First-In First-Out
GIS - Geographical Information system
GPS - Global Positioning System
ID - Identification
IMTT - Institute for Mobility and Land Transportation
LIFO - Last-In First-Out
NAL - New Lisbon Airport
OECD - Organisation for Economic Co-operation and Development
SWOT - Strengths, Weaknesses, Opportunities, Threats
TAP - Transportes Aéreos Portugueses
TGV - Train à Grande Vitesse (High Speed Train)
TX - Texas
UK - United Kingdom
U.S. - United States
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Chapter 1 – Introduction
1.1. Objectives and motivation
Airports are nowadays multimodal, multi-service platforms, with intense non-aeronautical activities
that cover several different industrial, economical and social areas. Taxi services are a fundamental
piece of the transportation diversity an airport requires, in order to become attractive and efficient.
They provide quick, comfortable, door-to-door service alternatives to a lot of passengers who wish to
travel within, to and from the “airport city” and, in some cases, they are even the only transport means
to connect the airport with the populated areas.
The main objective of this dissertation is to analyze, through the consideration of a case-study -
Portela Airport - the current operational and regulatory design options in systems of taxi service
provision, namely at airport passenger buildings, and propose, based on its performance levels, new
and alternative schemes and possible interventions that can improve the existing services.
This issue is often subject to intuitive thinking and political pressure when building or re-designing
of the system, many times leading to inefficiencies, excessive waiting times and/or low-quality of
service. The way taxi services are organized at the airport taxi stands also impacts the quality of
service and thresholds for efficiency gains at the terminals themselves. Reliability of service is a key
feature for passengers boarding flights at that terminal and availability and lower waiting times at the
taxi stand are important to arriving passengers who wish to quickly get to their destination after a long
trip. Flexibility is an important element to include in this framework, since airports are nowadays
dynamic infrastructures, which are often forced to grow or re-adapt to changing air transport market
conditions and, like most transportation hubs, are subject to significant peak-hour solicitations. This
aspect should be taken into account in the analysis of fleet dimensioning, regulatory aspects, service
types, queue design, depot and queue capacity options, etc. Most features of this analysis will be
addressed by the implementation of a simulation model for the queuing system at an Airport Terminal
taxi stand, based on real data collected in situ.
In recent years, Portuguese society has been intensely discussing the construction of a new
International Airport for the city of Lisbon. After some political turmoil regarding the future location for
this important infrastructure, the government‟s decision of building at Ota changed to Alcochete,
mainly due to public opinion pressure. Recently, the first drafts and initial details of the project have
been exposed to the public eye, but there is still some way to go until the first brick is in place and the
first aircraft lands at Alcochete. This major project, still in its early stages of development, opens a
window of opportunity to contribute towards the brainstorming and discussion on the design options of
the taxi service at the new airport and provides an excellent candidate for a case study – the soon-to-
be-replaced, Portela Airport. This opportunity, coupled with the almost absence of acknowledged
studies on airport taxi service performance and design in scientific literature, also provides this theme
with a substantial level of relevance, yet framed within a reasonable complexity context.
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Description:Dissertação para obtenção do Grau de Mestre em Throughout this academic adventure, there were many times when I wondered on the actual.
