Abstract—This paper discusses the advantages of using radio

frequency identification (RFID) technology embedded in fare smart cards as a transit management and planning aid. It is shown how RFID can be used for systematic collection and analysis of passenger flows, thus providing useful information for transit operations management and short term planning. Additionally, in combination with intelligent transport systems (ITS) technology, RFID can also provide support for infrastructure and fleet management activities, as well as real time information for transit user. Keywords— Radio frequency identification (RFID), passengers,

public transportation, services management, smart cards and control of infrastructure.

I. INTRODUCTION OR several decades, urban growth has contributed to

saturation of the structures which support citizens’ everyday lives [1], with direct impact on the ability of many cities to warrant a healthy life for their population and to secure adequate supply support structures. Such situation leads away from the ideal conditions to sustain a good urban life quality [2].

It should be noted that as a result of this, some cities display an increase in the rate of traffic accidents and fatalities, increasing problems related to air pollution, an increasingly insecure environment, rising cost of living and rising rates of unemployment, poverty and social exclusion [3].

Aware of this condition, rulers, administrators and organized urban communities are seeking for solutions that support the construction of public policies to address current

M. Lima is project coordinator of São Paulo Transporte - SPTrans, R. Boa

Vista n.236 , São Paulo/SP, Brazil, CEP 01014-000, and a PhD student at Escola Politécnica of the Universidade de São Paulo (Polytechnic School of the University of São Paulo) (mauriciolima7@usp.br).

J. A. de Golveia is systems analyst of São Paulo Transporte - SPTrans (jose.golveia@gmail.com).

E. Facchini is a member of the technical advisor to the planning board of SPTrans (eduardo.facchini@sptrans.com.br).

M. S. Pokorny is a PhD student of Polytechnic School, University of São Paulo – USP and a researcher of GAESI (melissapokorny@pea.usp.br)

E. M. Dias is full professor of the Escola Politécnica da Universidade de São Paulo (Polytechnic School of the University of São Paulo) and coordinator of GAESI - Grupo de Automação Elétrica em Sistemas Industriais, a reseach group of the Electrical Energy and Automation Department, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, trav. 3, n. 158, São Paulo/SP, Brazil, CEP 05508-970 (emdias@pea.usp.br).

and future challenges in cities [4]. The issues related to urban mobility of people, goods and

services are among the priorities and, like other cities, São Paulo, Brazil, has adopted restrictive measures to minimize negative impacts on traffic and congestion of roads: (a) in 1997 a license-plate-based car rotation scheme, by which 20% of the car fleet is excluded from expanded CBD traffic on work days [5]; (b) 2007 marked the beginning of the metro rail network expansion plan which, when implemented, by 2018, will have increased the metro network to 200 km, tripling the current extension [6]; (c) in 2008 restrictions to truck traffic were implemented at certain times of the day within a geographic area in the expanded CBD [7]; (d) in 2011 an extensive program of pedestrian priorities was adopted [8]; (e) 2012 saw an increase in the number of streets and avenues with reduced maximum speed limit [9]; and (f) between 2013 and 2014 over 300 km of bus lanes were dedicated, giving priority to this mode of transport over individual motorized transport [10].

Actions such as those aim at cutting congestion and reducing the impacts of emissions and deaths from traffic accidents, attracting drivers and passengers from private cars to mass transit, and stopping the trend towards saturation of important roads, thereby improving urban mobility.

Many traffic experts agree that besides improving the mobility of people living in the cities, accessibility gains are also vitally important. Accessibility is characterized by many authors as "the ease (or difficulty) for people and goods to reach parts of the city, as measured by the time and cost involved" [11][12].

On the other hand, Brazilian cities witnessed growing migration of economic activities to business complexes and shopping malls, and also increasing concentrations of multistory residential buildings, as well as other high-rise developments including universities, supermarkets, convention centers, etc.

Additionally, while there is no compromise in land use development, the upsurge of new business, services and industry concentrations open up new working and shopping opportunities, generate additional travel needs which have to be satisfied. All of these are categorized as “traffic generation poles”, as they bring up increasing traffic problems and additional restrictions to the displacement of people, goods and services [13].

Real time monitoring of public transit passenger flows through Radio Frequency Identification - RFID technology embedded in fare smart cards Maurício L. Ferreira, José A. M. de Gouveia, Eduardo Facchini, Melissa S. Pokorny, Eduardo M. Dias

F

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Monitoring and understanding travel patterns of individuals becomes an important field of knowledge to promote proposals towards improving urban mobility and accessibility, especially provided by public transportation systems.

II. APPLICATIONS OF ITS The city of Sao Paulo has a network of public transport

(metro, trains and buses) which has been consolidated over the years. Bus services, which are managed by the Municipality, include 1,300 lines which are operated by a fleet of 15,000 buses over a 4,500 km street network. These buses run 190,000 daily vehicle trips, serving a patronage of 3.7 million which perform a total of 9.5 million daily person trips.

Since 2004, the city has benefited from Intelligent Transportation Systems - ITS resources to support the management of bus transportation services. All transit buses are equipped with Automatic Vehicle Location (AVL) and Global Positioning System (GPS) devices, as well as with electronic fare validation devices – AFC. Bus stops in exclusive bus corridors are interconnected by optic fiber networks and are equipped with Closed Circuit Television (CCTV) cameras and Variable Message Signs (VMS). Bus terminals are monitored by CCTV cameras and information is conveyed to users via multimedia devices, PA systems and VMS panels that inform the departure and arrival time of vehicles [14].

Electronic ticketing has also been in use since 2004. The vast majority of passengers pay for their trips using city-issued smart cards trademarked "Bilhete Único" (Single Ticket), of which roughly seven million are in current and frequent use (at least once a week). Only 5% of all bus transit users pay the fare value in cash [15].

The digital data collected from transactions with smart cards, are used exclusively to support the fare revenue clearing process involving the city bus management agency and the rail operators and to establish the payment due to each private bus operator company (all city buses are run by private companies through municipal concession contracts).

III. DEFICIENCIES Even though much of the Intelligent Transport System

devices collect data continuously, and processing systems make information available online, such information is basically used for monitoring purposes, the most often not leading to effective correction of operational activities.

IV. RFID The use of automatic identification (Auto-ID) in public

transport services has been evaluated by Information Technology and Communication (ICT) specialists as a possible add-on to ITS (Intelligent Transport System), as shown in Fig. 1.

Fig. 1 – Overview of the most important procedures Auto-

ID Source: Handbook Fundamentals and Applications in

Contactless Smart Cards and Identification (2003) RFID technology has been widely discussed by companies,

the technical community and specialists, and an extensive amount of existing literature, regarding its description and applications. Used by the military since World War II, is now considered as an alternative to bar code technology, RFID has the advantages of streamline processes and is able to store relevant information as well as transmit wirelessly to compatible interrogators without physical contact.

The barcode, used since 1940, is currently very popular for product identification. However, RFID had been in commercial use since the 1970s, is gaining momentum and becoming relevant for industry, business, services and government agencies, is also being used in a variety of applications such as: supply chain control (logistics), product tracking (agenda control), authentication (quality control), property access control (security), anti-theft systems (security), individual documentation and identification (passports and hospital patients data), electronic payment (smart cards and tolls) and smartphones (NFC - Near Field Communication).

Radio frequency identification (RFID) technologies are based on devices assembled from miniaturized components consisting of: 1) Receiver called “TAG” or “TAG-RFID” which includes a

coil antenna and a microcircuit; 2) Read/Write equipment (transceiver) and their antennas; 3) Middleware modules to integrate field equipment to data

processing systems. The use of this technology allows the tag (in objects,

products or people) to be recognized and identified at a distance by means of electromagnetic wave emissions. As to the way of being energized, receivers can be classify as active, passive or quasi-active (or quasi-passive).

In this paper we deal specifically with low cost passive power receivers, which only require electromagnetic waves emitted by dedicated antennas to be activated. Once activated, the receiver will be able to start transmitting data to the

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reading equipment. The frequency bands used are LF - low frequency of 125kHz and HF - high frequency of 13.56 MHz, both also used in smart cards for connection with on-board fare readers and UHF - Ultra High Frequency (860MHz - 960MHz), also used in EPC (Electronic Product Code) systems. Microwave systems (2.45 GHz) are also used in some applications.

V. METHODOGY This article discusses the use of low-cost RFID technology

associated to infrastructure (vehicles, bus stops, transfer terminals, checkpoints on the route of the lines, etc.), and in combination with the technologies used in smart cards [17].

The first part of methodology is based on the installation of receivers and / or readers in public transport infrastructure components, such as buses, bus terminals and passenger boarding and alighting points along bus routes, as follows:

In Buses: installation of labels and reader equipment; In Terminals: installation of labels at passenger boarding

and alighting locations, and installation of readers with antennas near vehicle exit or entrance areas;

At Bus Stops: installation of labels (tags). The second part deal of the coexistence of smart card radio

frequency technology as used by the “Bilhete Único” (NXP MIFARE ® Classic) with RFID technology.

For the development, the SPTrans -the São Paulo Public Transit Management Agency -, had the company NXP Semiconductors perform a test and evaluate the recognition by reader devices installed in buses of a RFID tag embedded into a “Bilhete Único” fare payment smart card.

According to this methodology, a single sequential number is stored into the microchip tag (N-Bits transponder Read-Only system).

The stored number will be associated to the individual identification number of the smart card to which the tag is attached, allowing the tag, when activated, to transmit it as identification information to the reading device (reader). Thus, the records obtained correspond exclusively to the smart card to which the tag is attached. The proposed card structure is shown in Fig. 2.

Fig. 2 - Example of smart card with RF technology and smart card with embedded RFID technology. Source: Ferreira 2013

VI. OPERATION OF THE PROPOSED SOLUTION Through the antennas, an RFID reader can transmit

electromagnetic waves and perform more than 100 readings per second from transmitters up to seven meters distant from the antennas in free area. Thus, a prospective passenger bearing a smart card which has RFID devices attached to it will be promptly recognized and identified as he approaches the bus. Fig. 3 shows a schematic diagram of passenger card tag reading as done by the bus equipment and by the bus stop equipment.

Fig. 3 – Schematic view of automatic identification through

RFID technology. Source: Source: Ferreira 2013

This process will continue until the passenger's card is carried beyond the reading range of the bus interrogator antennas. When the passenger gets off the bus and moves away from it, and consequently carries the smart card equipped with RFID TAG away from the reach of the bus antennas the records in the card will no longer be transmitted. If the bus stop also equipped with RFID tags, then the smart cards carried by the passengers waiting for the bus, may have their tags activated and recognized by bus RFID devices.

To avoid receiving and processing an excess of repeated information from the same cards, while they remain within the range of the bus RFID readers, it is proposed that bus readers will be activated only while vehicle doors are open for passenger boarding and alighting. Thus, there will be no data collection while the vehicle is moving.

The data processing system (middleware) will identify the number associated with the RFID tag embedded into a specific smart card and compare it with the identification number of that smart card, as identified during the process of fare validation. Only if the two numbers are compatible will the system process the information received from that specific tag.

At terminals, a reader equipped with antennas installed near the bus entrance and exit gates will recognize and identify the vehicles as they enter or leave the terminal premises, and each event will be registered together with the respective date and time information.

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VII. THE EXPERIMENT There were some initial doubts as to the compatibility of

bundling RF identification technology with smart card technology. The main concern was about the efficiency and reach of electromagnetic waves for tag reading, considering that the bus environment is essentially metallic, that its space is mostly occupied by a variable number of passengers, and that 70% of the human body is liquid content.

These difficulties are enhanced by the fact that, unlike artifacts a production line that have their tags affixed to the outside, generally respecting certain fixed patterns, and within an environment that is free from major constraints for the propagation of electromagnetic waves, persons behavior is random and independent, as they constantly and rapidly move about, even in restricted spaces. The fact that passengers normally keep their smart cards protected (hidden) in purses or wallets until the time comes to present them before a validator interface to pay the fare and unlock the turnstile does not help either.

The experiment was prepared with the purpose of checking the efficiency of inside-bus tag readers, and evaluating the capacity for reading smart-card-embedded tags carried in bags, packets, shirt pockets, trousers pockets, bundled with books, in wallets and with cell phones, simulating commonly encountered situations.

A bus was then equipped with a reader and two antennas which were positioned inside the vehicle and near the entrance door (Fig. 4).

Fig. 4 - Buses equipped with equipment of radio frequency

identification technology. Source: Experiment. In the course of the experiment five volunteers boarded the

bus, one after another, each carrying a different tag in hidden locations (in objects or clothing). This experiment evaluated products from four manufacturers and different designs, which were tested one after another to compare their performances, while the volunteers kept their tags hidden in the same position. Volunteers approached the bus, proceeded to the gate, boarded (passing between the antennas), walked down the vehicle aisle to the validator and then got off. The observations and findings were presented in Table 1.

Table 1 – Results of the experiment.

Source: Experiment performed by NXP Semiconductors

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All tags tested were successfully energized and returned

information, but variations were observed as to the time required and the number of readings which were transmitted in each collection cycle.

VIII. POTENTIAL OF OBTAINING DATA The RFID technology can be used for data acquisition and

processing of important information for the management of public transport. In this project the following information is obtained: 1) Punctuality and frequency of transport services at

checkpoints; 2) The quantity of vehicles that are in operation, their ID’s

and real time positions; 3) Travel time averages of passengers; 4) Vehicle delays at intersections, bottlenecks and other

relevant locations; Radio frequency technology, as used for communication

between buses and their infrastructure, makes it possible to constantly confirm the bus actual position, as related to established check points, thereby allowing real time scheduling control and adjustments.

It can also provide tools for updating infrastructure and

vehicle inventory information. On-board equipment allows following groups of “tagged” fare smart cards since the moment their bearers approach the bus for boarding, and continue following them while they are aboard, until the moment when they get off and the bus moves away.

Thereby, passengers boarding and alighting at each stop can be counted, and each of the boarding and alighting stops can be identified by association with fare card ID number. Such information will also allow us to confirm data obtained by GPS giving conditions to retrieve monitoring in cases of system breakdowns. Thus qualifies Operational Control Centers perform online actions to correct the chain of services every time.

Once in regular operation, the system shall routinely yield information which, once available, may widen the regulatory scope of Operation Control Centers, providing adjustment inputs to the system network and allowing short-term planning, and improvements in information to passenger. Fig. 6 shows an overview of the data processing subsystem (middleware) and respective connections.

Fig. 6 - Overview of the data processing subsystem (middleware) including tasks and connections. Source: Author.

While managing demand of passengers, the system gives

access to passenger displacement patterns and brings forth additional possibilities, including: 1) Counting the number of passengers which remains on the

bus between each stop, allowing the identification of the highest load section along the bus route.

2) Number of passengers getting on and off the bus at each bus stop;

3) Number of passengers on board of the bus between each pair of subsequent bus stops;

4) Passengers travel time on board of the bus; 5) Total passengers public transportation travel time

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(excluding trip end walking times); 6) Plan new services in response to variations in passenger

origin and destination survey information; This information expands the conditions for efficient

management of urban public transport and improve quality of services. Such information will lead to urban mobility and accessibility improvement and support appropriate public policies towards efficient transport system. Some benefits may include: 1) Savings financial resources with a perspectives for

expanding infrastructure use management; 2) Better performance and efficiency of public transportation

services; 3) Ensuring a better public transport by providing higher

quality systems with improved service levels; 4) Development of urban mobility plans more compatible

with the growth and functionality of cities; 5) Provision of relevant information supporting users’

decisions on how and when to use public transport services;

6) Lowering transit management costs through a increase efficiency of use of human, financial and time resources in the development and implementation of passenger behavior or transport system operation surveys systems or research about characteristics of passenger demand;

7) Impart on proactivity of Transit Operations Control units; 8) Synchronization of bus services in order to minimize

transfer waiting times of passengers; 9) Implementation of fraud detection routines to curb undue

smart card usage practices; 10) Contribution to a technological innovation-friendly transit

environment (V2I, V2V, I2C, IOT, etc.); 11) Development of plans for increment traffic attraction

zones and attain balanced and sustainable land use patterns supported by efficient urban transport systems;

12) improvement of the quality of life of urban population by creating facilities that are appropriate to their daily needs;

13) Expanding tourist infrastructure; 14) Establishing comprehensive and dedicated transport

system connections between public services facilities; 15) Creating tailored services dedicated to specific public

transport user categories, like: students, senior citizens, disabled and others;

16) Providing updated information on passenger displacement patterns, which can be used for calibrating future transport network models;

However there are still difficulties to be overcome in order to consolidate the applicability of the RFID, such as: 1) Improvement of functionality of transponders so they

become better suited for operation in areas with high density of passengers;

2) The cost-effectiveness analysis (considering time and money) of replacing current smart cards by cards with radio frequency identification technology;

3) Evaluation of the costs of acquiring, installation and maintenance of the tag readers, in buses and terminals, and compare them to expected benefits;

4) Evaluation of logistic efforts and costs associated with the installation of TAGS onto current bus stops;

5) Integration of data communication between the new devices and electronic equipment already installed in buses;

6) Development of the computational architecture and communication infrastructure that support the operation of the technology;

7) Development of data processing and producing information in user’s interfaces (internal and external) systems;

8) Development of procedures to ensure efficient use of the information through actions, incorporating them in training.

IX. CONCLUSIONS This article presents possible solutions for obtaining

information arising from the use of radio frequency technology identification - RFID in urban public passenger transport systems and indicates the way for future discussions on the use of transit fare payment smart cards as a physical support for RFID devices.

The wide applicability of such resource is related to the ever growing adoption of smart electronic ticketing and vehicle monitoring systems, which have already been implemented and are in use in many cities worldwide, Sao Paulo being one of them. Since smart cards are commonly carried along by the public transportation systems users, they appear as potential providers of information concerning transit services.

The radio frequency identification components fulfill their role in monitoring the displacements of user’s due to use of smart cards in their travels and thus appear as potential supplier of information. Moreover, adding it to travelers cards does not affect the current use of smart cards for electronic fare payment and does not require any specific action from the user in its daily card’s maintenance.

However, recognition of the smart card identification data will provide information and control of time and place both users and vehicles.

Thus, the use of RFID and smart card infrastructure and public transport vehicles, justifies necessity for the creation of indicators and control of time, places, and consumption of services by users conditions, as well as collecting additional information on resources and infrastructure buses.

This paper discussed benefits of use of the RFID technology devices embedded into fare payment smart cards to public transport. Experiment results indicate that the efficient use of such technology does not require any change in the use of public transport fare payment smart card by passengers.

The use of RFID has the advantage of complementary information obtained by existing ITS systems and produces new information for the management of bus infrastructure and support users in real time. Allows to develop control systems for the passenger demand and systematizes and updates matrices of origin and destination (O/D) about the travel of passengers in bus systems and get their volumes. This

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information is important supplement to implement improvements in urban public transport network.

Although with challenges, the use of RFID technology enables promising information about the characteristics of patterns of passenger’s displacement and efficient use of infrastructure and resources of public transport. The use of RFID technology for providing of demand-related information about public transport system to its operators. The system can be effectively developed in the coming years, bringing number of benefits to passengers and contributing to the organization of sustainable cities. That is way it deserves attention and should be further development.

REFERENCES [1] GUPTA, J. Global Sustainable Development Governance: Institutional

Challenges from a Theoretical Perspective. International Environmental Agreements: Politics, Law and Economics, v. 2, n. 4, p. 361-361, 2002.

[2] TOPPETA, D. The smart city vision: how innovation and ICT can build smart, “livable”, sustainable cities. The Innovation Knowledge Foundation, 2010.

[3] BATAGAN, L. Smart Cities and Sustainability Models– Informática Economica, vol. 15, p. 81, nº3/2011.

[4] INFOSYS - Innovation and the City - Rapid urbanization is creating opportunities for new technologies to make a new difference. Girish Khanzode, Shekhar Potnis. In: Insights - Building Tomorrow's Enterprise, p. 1, 2012.

[5] Decreto Municipal Nº 37.085 de 3 de outubro de 1997 - Regulamentação da Lei nº 12.490 que autoriza o Executivo a implantar o Programa de Restrição ao Transito de Veículos Automotores.

[6] Folha de São Paulo – Caderno Cotidiano – Alkimin promete mais 126 km de metrô em São Paulo até 2018, em 19/04/2012, em – http://www1.folha.uol.com.br/cotidiano/2012/04/1078302-alckmin-promete-mais-126-km-de-metro-em-sao-paulo-ate-2018.shtml. (Acesso em 05/03/2014).

[7] Diário Oficial da Cidade de São Paulo, Nº 87 (13/05/2008) - Decreto Nº 49.487 de 12 de maio de 2008 - Regulamenta o trânsito de caminhões na Zona de Máxima Restrição de Circulação - ZMRC.

[8] Programa "Dê Preferência à Vida" - Zona de Máxima Proteção ao Pedestre - ZMPP - disponível em http://www.cetsp.com.br/consultas/zona-de-maxima-protecao-ao-pedestre.aspx (Acesso em 01/03/2014).

[9] Premissas para um plano de mobilidade urbana – Associação Nacional dos Transportes Públicos - ANTP/Secretária Municipal dos Transportes – SMT / São Paulo Transporte S.A. - Sptrans, 2013.

[10] Programa "Dá Licença para o Ônibus" - A cidade que a gente quer é aquela que dá prioridade ao transporte público - disponível em http://www.cetsp.com.br/consultas/da-licenca-para-o-onibus/o-programa.aspx (Acesso em 01/03/2014).

[11] VASCONCELLOS, E. A. - O que é o trânsito. São Paulo: Brasiliense. P. 26., 1985.

[12] GOMIDE, A. A. Mobilidade urbana, iniquidade e políticas sociais. Políticas sociais: acompanhamento e análise, 12, p. 242-250, 2006.

[13] Departamento Nacional de Transito – DENATRAN - Manual de procedimentos para o tratamento de polos geradores de tráfego. DENATRAN/FGV, Cap. I, p. 7-8. Brasília, 2001.

[14] São Paulo boosts bus reliability by 30 percent, ups innovation with outside help - Microsoft Case Studies - http://www.microsoft.com/casestudies/Case_Study_Detail.aspx?CaseStudyID=710000001378. (Acesso em 01/03/2014).

[15] Smarter e-ticketing for Sao Paulo – NXP – Global Press Release - http://www.nxp.com/news/press-releases/2013/07/smarter-e-ticketing-for-sao-paulo.html - (Acesso em 08/03/2014).

[16] Handbook Fundamentals and Applications in Contactless Smart Cards and Identification, Overview of the most important procedures self-ID – RfiD, Second Edition - John Wiley & Sons 2003.

[17] FERREIRA, M. L. - RFID for Real Time Passenger Monitoring – WSEAS – World Scientific and Engineering Academy and Society: Recent Researches in Telecommunications, Electronics and Signal Processing, 2013.

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