A New Passenger Support System for Public TransportUsing Mobile Database Access

Koichi GOTO Yahiko KAMBAYASHI

Railway Technical Research Institute Kyoto University, School of Informatics2-8-38, Hikari-cho, Kokubunji-shi Yoshida-Honmachi, Sakyo-ku,

Tokyo 185-8540 Japan Kyoto 606-8501 Japangoto@rtri.or.jp yahiko@i.kyoto-u.ac.jp

Abstract

We have been developing a mobile passengersupport system for public transport. Passen-gers can make their travel plans and purchasenecessary tickets by accessing databases viathe system. After starting the travel, a mo-bile terminal checks the travel schedule of itsuser by accessing several databases and gath-ering various kinds of information. In this ap-plication field, many kinds of data must behandled. Examples of such data are routeinformation, fare information, area map, sta-tion map, planned operation schedule, real-time operation schedule, vehicle facilities andso on. Depending on the user’s situation,different information should be supplied andpersonalized. In this paper, we propose anew mechanism to support passengers usingthe multi-channel data communication envi-ronments. On the other hand, transport sys-tems can gather information about situationsand demands of users and modify their ser-vices offered for the users. We also describe aprototype system developed for visually hand-icapped passengers and the results of tests inan actual railway station.

1 Introduction

The mobile computing technologies are rapidly grow-ing and spreading their application field [1, 2, 3]. Es-pecially supporting human activities in the outdoor

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Proceedings of the 28th VLDB Conference,Hong Kong, China, 2002

environment is one of the principal applications of mo-bile computing. As the public transport systems havevery important roles for the outdoor human activitiesespecially in the cities, it is indispensable for the mo-bile computer systems to have functions supportingthe utilization of the public transport systems for theusers. We have been developing a new mobile passen-ger support system for utilizing the public transportssuch as railways or bus transports[8, 9]. To realizethis type of system, various kinds of data must behandled and integrated. Examples of such data areroute information, fare information, area map, stationmap, planned operation schedule, real-time operationschedule, vehicle facilities, congestion information etc.Some of them are dynamically changing according tothe actual activities of the transport systems. More-over depending on the user situation such as desti-nation, current location, current time etc., differentinformation should be supplied. So personalized userinterface for handicapped and old people is especiallyrequired.

The support process of the system is as follows. Atfirst, the user of the system makes a travel plan byaccessing central database using mobile terminal. Thecenter system offers several plans that satisfy the re-quirements of the user. The user selects a plan andreserves tickets if necessary. After starting the travel,the mobile terminal accesses the central database orlocal databases and gathers various kinds of informa-tion and checks the schedule of the travel plan. Theuser can go on the travel according to the appropri-ate guide messages offered by the mobile terminal. Inthe outdoor field, there are two kinds of data sources,fixed and moving. The data of the local databases areoffered by two kinds of data sources, which are fixeddata sources and moving data sources such as trainsand buses. The data from the moving sources are tem-porarily supplied. Although most of user requests areprocessed by means of integrating broadcast type data,on-demand process should be also required.

The system must be used in the case of emergency

Figure 1: Current user situation and new user situation

when the system load is expected to be very high. Be-cause of this condition we will not use a centralizedsystem. Various kinds of data are transmitted to mo-bile terminals. Integration, personalization and filter-ing are performed at each mobile terminal. In thispaper we will discuss efficient methods to handle dy-namic integration, personalization and filtering usingmultiple data dissemination channels and on-demanddata channels. Current prototype system to be usedby visually handicapped passengers is also shown.

2 Requirements

One of the important applications of the very largedatabases is to support the activities of people movingoutdoor environments[4]. In outdoor fields, people canaccess many data sources such as web sites and get use-ful information from the digital world. And the userscan begin the next activities using that information.In case that the user goes around the cities , he/shemay utilize some public transport facilities. Actuallyin the central areas of large cities, public transportsystems execute very important roles. For supportingthe users of mobile information systems and relateddatabases, handling the information concerning withthe public transport systems is indispensable. When auser enters a control area of a public transport service,such as a railway station, the user should be able to getguide information about the railway utilization. Theinformation is filtered, personalized and integrated ac-cording to the personal situations of the user, such asthe location, favorite things and physical conditions.

On the other hand, the public transport systemsshould get useful information about passengers usingmobile communications, such as numbers of the pas-sengers, their destinations, future plans etc. The ser-vices of the transport can be changed according tothe real-time demands. This scheme is not possibleby the current operation systems of public transports.Acquiring the real-time demands of the passengers isdifficult. The bi-directional relation between passen-gers and systems is a very important research theme.

If the transport systems have abilities to change theirservices according to the demands, the system can of-fer more convenient environments for the passengers.Using the proposed passenger support system, the in-formation from the passengers can be gathered andoffered to the public transport systems. Although ser-vices may be adaptively changed according to the de-mands, the public transport systems are not able tooffer an individual service for each user because theyare ’public’. It is impossible to satisfy all the passen-gers perfectly, because the services have tendency toanswer to the average requests. So it is very importantto inform passengers of current conditions of servicesand offer personal guide messages, such as “what todo next”, “how to do that” and “where to go next” tosatisfy his/her own demand. One of the objectives ofour research is to realize such services.

3 Solutions

To utilize the public transport, a passenger needs var-ious kinds of information. They must know transportservice networks and what kinds of services are offered.Additionally there are many kinds of information to beknown as mentioned in the previous section. The pas-senger must gather necessary information and decidetheir next actions. The left side of Fig. 1 shows thissituation.

Suppose you are the passenger and you have an at-tendant. When you would like to go somewhere, youwill tell the attendant the destination of the travel.The attendant will consult timetables and ask rail-way operators about the information of the conges-tions and reservations, and finally propose you severaltravel plans. You will choose one of the plans, consid-ering your preference, budget, etc. The attendant willmake necessary arrangements for the travel. In themorning of the travel, the attendant will come to yourhouse to pick you up. Transport modes that will beused on the day would be public transport fundamen-tally. As the attendant knows the current condition ofthe transport, you will be required to follow what the

Others systems

Central databasesGlobal network

Multiple data channels Multiple data channels Multiple data channels

Local databases Local databases Local databases

Mobile terminal

Station 1 Station 2 Station n

Figure 2: System configuration

attendant says, even if there are some changes from theoriginal plan. The attendant could explain sights tosee when you are lonely or remain silent when you aresleepy. Even if you miss the targeted train, you don’thave to run in the station to get the next train reserva-tion. The attendant already arranged or is arranginga new plan. You can change your travel plan anytime,just by telling the attendant what you would like. Ifyou would like to drop in at a shop or a restaurant,the attendant will give you enough information. Youdon’t have to think about the fare calculation even ifyou changed your travel plan. The fare would be min-imum as if you know what you had done beforehand.If some of your relatives would like to know where youare, the attendant could inform him/her of your po-sition if you allow the attendant to do so, this wouldbe very convenient service to guardians. If you re-ally could have this attendant free of charge or reason-able cost, you would not be bothered by travels usingpublic transport? We think that we could realize thisbusiness model using information technologies and thismodel will give passengers and public transport opera-tors much benefits. If we could realize this mechanism,the attendants would do the current jobs being doneat a station. Therefore, conventional station functionsare no more necessary. The new functions of a stationwill be a contact point between a cyber space and a realspace, such as in electronic commerce. This indicatesthe changes of business model of public transport.

Our solution is to develop a personalized supportsystem using a mobile terminal working as the atten-dant mentioned above. The mobile terminal shouldhave functions to collect information, make travelplans according to the user’s requests, purchase nec-

essary tickets and guide the passenger on the all theway of the travel. Although on-demand communica-tions are suitable for making plans, broadcast commu-nications are necessary for real-time guiding in servicefields. The reason is that there are a vast number ofpassengers in the same area and the system must beused even in the case of emergency when the systemload is expected to be very high. So we have adoptedthe decentralized system in which the mobile termi-nals act a main role for supporting passengers. In thisenvironment a user can ask a question to the mobileterminal at any time and any place, and he/she canget an appropriate answer from the mobile terminal.The right side of Fig. 1 shows this new situation.

Integration, personalization and filtering are per-formed at each mobile terminal. Depending on theuser situation such as destination, current location,time etc., different data should be supplied and person-alized user interface for handicapped and old people isespecially required. Although most of user requests areprocessed by means of integrating disseminated data,on-demand process should be required for purchasingtickets on site or other transaction based requests. Itis necessary to provide multiple communication chan-nels, some for data dissemination and others for on-demand processing.

4 System configuration

The basic system configuration of the proposed pas-senger support system is shown in Fig. 2. There arebasically three components in the system, namely cen-tral databases, local databases and mobile terminals ofusers. The mobile terminals can communicate by bothon-demand mode (mainly with the central server) and

broadcast mode (mainly with local servers and movingdata sources).

4.1 Databases

4.1.1 Central databases

A passenger can communicate with the central serverdirectly using on-demand channel including Internet.The central server has its own databases containing in-formation about the transport services such as trans-port network, fares, station map, operation schedulesetc. The central server is connected to other systemssuch as seat reservation system for supporting pas-sengers in several aspects. Generally the informationgiven by the central server is not so detailed, but ofenough level to make travel plans. The detailed in-formation can be given in service fields such as rail-way stations. The central server also gives the follow-ing information concerning local data channels: Types(broadcast or on-demand), frequencies, contents, dataorganization structures, service locations, timing andconditions, etc., which the mobile terminal must knowto get necessary information in the actual travel phase.

4.1.2 Local databases

The servers of the local databases are placed at servicefields such as stations. The central server can delivercommon information of the transport system to theusers in the fields via local servers. A local server sendsthese common data to passengers with the followinglocation dependent data using several communicationchannels.

• Detailed station map

• Operation schedules of trains departing from andarriving at the station

• Platforms related to trains

• Real-time operation information

• Information about shops and restaurants etc.

• Other facilities in the station

4.2 Data sources in the traveling fields

4.2.1 Fixed data sources

A fixed data source disseminates data from a fixedplace. If the contents of a channel are geographicaldata of a station, the transmission area is within thestation. If the contents are data about a shop, thetransmission area is the neighborhood of the shop andthe data are provided during the time when the shop isopen. If the contents are the total operation scheduleof trains, the transmission area may cover all the re-gions of the railway. Same radio frequencies are sharedby different data sources geographically and timely.

Some channels are used for on-demand informationretrieval. By connecting with the central server orlocal servers, mobile terminals can retrieve informa-tion and execute some transaction type processes. Thenumber of channels, however, is smaller than the num-ber of the passengers of the site, so some connectionrequests may be rejected. Fig. 3 shows the image offixed data sources.

4.2.2 Moving data source

Trains and buses also broadcast data about their oper-ations (time table, stopping station list etc., accommo-dation and facilities etc.) as moving data sources. Pas-sengers can get accurate information about the trainoperations. Even if trains of different destinations willcome at the same platform, the mobile terminal canreceive the data from the current train and tell theuser to ride it or not according to the destination ofthe user. Moreover, if necessary, the mobile terminalcan make or remake the schedule of the passenger onsite. This function is very useful for visually or aurallyhandicapped passengers because the guide informationis given by visual or voice messages in the public trans-port and these passengers cannot use some of them.Fig. 4 shows the image of a moving data source.

4.2.3 Data access method

There is a directory channel in every local area. Themobile terminal can check the channel and know howto get necessary data using data channels. As for theaccess method to each channel, we can use the resultsof the researches for channel efficiency and saving ofthe battery of mobile terminal [5, 6, 7]. The usermay get data of the same attribute from the differ-ent sources in different granularity. Generally a userwants to see which station are the starting station andthe ending station in the planning phase and need notknow the detailed structure of the stations. If the userwants to get details in the planning phase, the cen-tral server can search the location of the informationand retrieve it. The granularity of the same item maychange according to the following channels;

• Global information network (Internet level)

• Local area channels (Station level)

• Small area channels (Facilities or utilities level)

• Moving channels (Vehicle level)

4.3 Mobile terminals

Each passenger has a mobile terminal. There is a soft-ware agent having abilities to support the user’s travel.The abilities are such as;

• to retrieve data according to the requests of theuser

Figure 3: Image of fixed data sources

Figure 4: Image of moving data sources

• to make a travel plan that satisfies the requests ofthe user by communicating with the central server

• to offer appropriate guide messages by integratingand personalizing information for the user

• to check the conditions of the public transportservices

• to modify the travel plan according to the actualservice conditions

The agent can use personal data of the user andthe past travel records. The agent supports the useractivities using the central server and local servers ac-cording to the user’s requests and personal data. Forhandicapped passengers, mobile terminal should havesuitable user interface for them. Namely for visuallyhandicapped passengers, mobile terminals should com-municate by means of voice.

The functions of mobile terminals are divided intofour categories. These are user interface, informa-

tion management, communication control and ma-chine control.

1. User interfaceFunctions of this category are for the communi-cation with the user. Though normally the mo-bile terminal has buttons for input of data orcommands and some display for information out-put. Voice communication method is importantbecause of the restriction of the size of the mo-bile terminal. As we will show in the discussion ofthe prototype system, oral communication is espe-cially useful for visually handicapped users. Func-tions for conversation control and user requestsmanagement are necessary for the high level com-munication with the user.

2. Information managementFunctions of this category are for management ofthe data and travel schedule. Several kinds ofdata are stored in the mobile terminal. Personal

data are used for personalization of data acquisi-tion and presentation. Some data such as trans-port service status, station maps are temporarilystored. The travel plan of the user is updatedaccording to the changes of the locations of theuser.

3. Communication control

Functions of this category are for channel com-munications. The mobile terminal monitors thedata channels and stores the status of channels.According to the situations or the requests of theuser, the mobile terminal gets data from the ad-equate data channel. The mobile terminal musthave the functions for on-demand communicationtoo. The function for acquisition of location datais included in this category.

4. Machine control

Functions of this category are for hardware mon-itoring and control. The monitored componentsare such as battery, memory space, input/outputdevices. The alarm message shall be offered tothe user if there are irregular situations.

5 Database access

5.1 Database access in travel planning phase

A user who wants to travel to some place can make atravel plan by accessing the central server using his/hermobile terminal as follows;

1. The mobile terminal has personal data about thepassenger, such as age, sex, physical conditionsand favorite places etc. beforehand.

2. The user indicates the destination, a rough sched-ule of the travel and other requests on the travelto the mobile terminal.

3. The mobile terminal communicates with the cen-tral server and makes several travel plans usingrelated databases and computing abilities of thecentral server.

4. The mobile terminal shows the candidate plans ofthe travel.

5. The user chooses one of the plans shown by themobile terminal.

6. The mobile terminal purchases or reserves nec-essary tickets for the plan. In future the digitaldata recorded in the mobile terminal shall workas tickets themselves.

7. The mobile terminal set the determined travelplan in it. The plan is used in actual travelingphase to guide the user.

The user can start the process at any time, even ifthe user is already in some station not at home. Theplanning of a travel is the start of a contract of thetravel. Once users get the guidance, they do not haveto buy tickets or consult timetables by themselves.The users don’t have to input the similar informationseveral times, where the current systems may insistthem.

5.2 Database access in traveling phase

5.2.1 Travel plan

As mentioned above, after starting the travel the mo-bile terminal has the concrete travel plan of the passen-ger. The mobile terminal gets the several informationsuch that locations of the passenger, operation sched-ule of vehicles, information about the facilities of sta-tions and so on. During the travel, the mobile terminalchecks the travel plan and offer the passenger appro-priate guidance as the attendant of the section 3 does.The executed parts of the travel plan are memorizedas the records of the actual travel of the passenger asshown in the Fig. 5.

If the passenger set the mobile terminal in the “be-ginner mode”, it can start from “guidance on the warn-ing just before the departure time, followed by theroute guide to a station, and provision of detailed in-formation inside the station”. When a change of vehi-cles is required, it will tell the passenger where he/sheshould change trains, considering the current train op-erations. In case of disruption of train schedule, it willshow alternative routes depending upon the situationand personal preference, as if a faithful and profes-sional travel agent paged him. If a passenger knowsthe route very well and is annoyed by such functions,he/she could switch off the service, telling the systemthat no announcement is necessary except a big changehappens.

The integration method of information is a veryimportant issue of the support system. The mobileterminal should present personalized information in aconsistent manner in spite of the change of channelsand their contents according to the movement of theuser and the situation of the transport services dynam-ically. As passengers don’t want to know the detailsof the system structure, information must be seen asif it is given from a one large database reflecting theenvironments. The support procedures in the normalsituation and the emergency situation are shown be-low.

5.2.2 Normal procedure

The outline of the normal procedure in the case ofutilizing railways is as follows. The user has alreadymade a plan before arriving at A station. The plan isto go to B station from A station via the route C untiltime D.

Original Travel Plan

(1)

(2)

Original Travel Plan Done

Done

Done(n)

Start of travel, Database Access

Database access, Travel plan checkInformation presentation to the user

Modified Travel Plan

Database access, Travel plan checkModification of travel plan

Iteration of the actionsat the check points

Some troublehappens.

Database access, Travel plan checkInformation presentation to the user

Modified Travel Plan Done(3)

Figure 5: Database access using travel plan

1. At the entrance of the A station, the mobile ter-minal checks the directory channel of A station.

2. The mobile terminal gets station map and trainoperation data from the corresponding channels.

3. The mobile terminal selects the train to ride forgoing to B station via the route C until time D.

4. If necessary, the mobile terminal reserves a seatusing on-demand channel. The mobile terminalmay works as a ticket itself.

5. Using the station map the mobile terminal tellsthe direction to go to the platform. If the userwants to see the message using a display, the guidemessage is shown on the display.

6. If the user wants to go to other places such astoilets or restaurants. The mobile terminal checksthe map and guides the user. During the walk, themobile terminal can get more detailed informationabout the route and destination.

7. After arriving of a train at the platform, the mo-bile terminal gets the data from the train andchecks whether the user should get on it or not.

8. In the train, the mobile terminal gets the sched-ule of the train and tells the user if there is anirregular situation or not.

9. Just before arriving at B station, the mobile ter-minal tells the user to get off.

10. After getting off the train, the mobile terminalgets the map of B station and guides the user tothe exit.

5.2.3 Emergency procedure

In the real environments, services may change accord-ing to some accidents or other irregular events. Insuch an emergency situation, it is necessary to informall the passengers of the current service status andmodify the travel plan. As there are a huge numberof passenger in the same public transport service areaand their objectives are different one another, it is con-sidered that communicating them through on-demandcommunication network is very difficult.

Our solution is that the directory channel gives anirregular signal and how to get the details of the cur-rent situation (mobile terminals check the channel pe-riodically). Each mobile terminal checks data channelsand examines whether it is necessary to change theplan of their users. If it is necessary, such mobile ter-minals start to make modified plans. The flow shownin Fig. 5. Of course the on-demand data channel maybe used to the limited number of mobile terminals (thenumber depend on the communication environment ofthe area). It is possible that a data channel sends soft-ware to improve the functions of mobile terminals.

6 Data acquisition from passengersand demand-oriented services

The data flow is not restricted only the direction fromthe system to users. When the users enter an area sup-ported by the system, the mobile terminal can commu-nicate with the system and register the existence anddemands (destination, desired arrival time etc.) of theuser. If the user need execute some specific process,he/she also executes it using the mobile terminal. Anexample of such a specific process is reservation of trainseats. By communicating with the users, the transportsystem can get the following information:

• The number of the users existing in the servicearea

• The distribution of destinations of the users

• The user flows of the transport network

• The possible users of other facilities in the servicearea, such as shops in the station

• The existence of users who need specific services,such as physically handicapped people

As for the railway, to change the operation sched-ules of trains is not easy because resources of cars and

Figure 6: Prototype mobile system

crews for trains are restricted and the frequent changesof work schedules may bring confusions. However thesmall changes are possible. For example the departingperiod between one train and the next train can bechanged. In case that many passengers miss a train ifthe train keeps on the original departing time, the timeshould be delayed according to the information aboutthe passenger flow. This kind of on-demand servicecan be adopted more easily for the operation of buses.Even for the railway, if the automatic operation sys-tem is adopted, the train operation re-scheduling canbe executed is more easily. In case that the frequencyof train operations is high, the train services may beoffered as if they were elevators moving horizontallyaccording to user demands.

Even if it is impossible to change the operation oftrains, the support system can advise users to avoidthe unbalance concentration. Namely the system cantell some of users which car they should choose.

The one of the procedures to acquire the user dataand is as follows;

• When a user enters into the some supporting area,the user communicates with the system to registerhis/her existence in it and tell his/her demands.The mobile terminal executes this process auto-matically.

• The system gives some number (or identifier) tothe user to be classified for getting informationafterwards. Namely the user belongs to the somegroups of which users have the same objectives.

• The user can get information by filtering thebroadcast data according to the given group num-ber.

This mechanism can make reduction of communica-tion loads. In the public transport system, generallydestinations of users can be classified into a small num-ber of groups. For example, at a station users can beclassified into two groups, one for riding trains boundfor Tokyo, and the other for riding trains out of Tokyo.

Trains may be divided into more classes, such as ex-press train and ordinary train and the each group maybe divided into more sub-groups. But the number ofgroups is considered to be not big. The group numberhas time restriction. If a number becomes timeout andthe user of the number remains in the same area, theuser must re-register for getting new group number.

The system can utilize this scheme to control usersfor improving environmental conditions of the area.For example, to distribute the flow of users in the sta-tion, the system can advise some groups to go throughone way and for other groups to go through the otherway. Of course users have liberty to choose any route.One-to-one communication is not suitable in case thata huge number of users exist in the same area. Thesystem we proposed here is a solution for such an en-vironment.

7 Prototype system for visually hand-icapped passengers

There are many handicapped passengers in transportenvironments such as disabled people (visually dis-abled, auditory or physically disabled persons, etc.),aged persons, pregnant women, small children, foreignpersons who can not speak Japanese and ordinary peo-ple who are not familiar with using transport facilities.The system proposed in this paper is very suitableto support these handicapped passengers and it canmake public transport systems friendly to use. We arenow developing a prototype system for visually handi-capped passengers as the first target [8]. Fig. 7 showsthe basic configuration of the system. To support visu-ally handicapped passengers, we need location data ofthe accuracy of at least 30cm because there are manydangerous places in the station, such as platforms. Wehave adopted the technique to embed RF/ID data tagsrecording location data under guide blocks for blindpersons on the station floor (Fig. 8). The mobile ter-minal can read location data through a cane in whicha small reader is installed. The communication dis-tance between the cane and data carriers is about 20

cm. The size of the mobile terminal is 145mm x 80mmx 20mm and the weight is about 240g including bat-tery. Fig. 6 shows a cane and a mobile terminal. Thesystem may use other location system such as GPSadditionally.

Figure 7: Configuration of prototype system

Figure 8: RF-ID tags embedded under the guide tileson the station floor

The prototype system can get location informationfrom the embedded RF-ID tags and other informationfrom a radio communication channel as shown in Fig.9. The mobile terminal is able to communicate withthe center server via telephone network too. All oper-ations of the mobile terminal can be done by voice andmessages are given by voice too. Every time the mo-bile terminal gets a location datum from a data carrier,it generates a message about the current situation bymapping the location datum with the station map. Ifthe user misses a message, it is possible to repeat themessage by saying ’repeat’. So visually handicappedpassengers can know where they are now and whichdirection they should go by using the mobile terminal.

The examples of these messages are as follows.- At the stairs: Here are downward stairs of 20 steps.- At the concourse: Here is a ticket vending machinein front of you. You are in front of a rest room.- At the platform: This is the platform No.3 or theplatform for XXX-line. This is the Hikari super ex-press No.51.- In the coach: This is the coach No.5.

It is also possible to make a more adaptive messageby setting a destination. The mobile terminal guidesthe user to the destination by voice. If the user is onthe wrong way, the mobile terminal makes an alarmsuch as ”Return to the last informed position and turnto the right”. If a passenger is in a dangerous situa-tion (for example, the user is walking on the edge ofa platform), the mobile terminal gives a beep soundalarm or vibration alarm of the cane. The scheme ofour system can be adapted to other kinds of disabledpersons. If the user is a person disabled to move, forexample, he/she can get information about equipmentto support him/her to move in the station, such as el-evators, escalators and slopes through his/her mobileterminal attached to his/her wheelchairs.

Data Communication

Conversation

Location Data

Figure 9: Database access in traveling phase

8 Field test in an actual station

We have conducted a field test in an actual station inTokyo metropolitan area. About one thousand RF-IDtags were embedded in the floors of a concourse anda platform of the station. The radio communicationequipment, however, has not been set in this test. Theparticipants in the field test for estimating the basicfunctions of the system were 10 real visually disabledpeople. We did not change or control the conditionsof the environment of the station, such as train sched-

ules, broadcasting voice messages and passenger flows.However, in the case where there was a dangerous situ-ation such that another passenger may hit the disabledperson, we intervened in to guard the disabled person.Before starting an examination, the participants weregiven the information about the improved points of thenew system and used it in the concourse of the stationfor getting accustomed with the usage of the system.

Then, we gave them three subjects to:(a) Walk from a place outside the station to anotherplace which is positioned in front of a train door on aplatform (there are steps in the route),(b) Walk using two kinds of guidance levels that differin their details of guide messages and compare them,and(c) Use the function by which the system gives theusers the information where they are now.

During their test walks using the system, we tookvideos with two video cameras, and recorded the guidemessages and the reactions of users on notebooks bywalking with them. A scene of the test is shown inFigure 8. By examining the results of the field test,we have confirmed that the functions of the systemwork effectively in actual stations too.

The considerations about the results of the test areas follows.

1. Move by voice guidance and navigationThe subject (a) is to walk from a point beforeticket vending machines to the point in front ofa specific train door on a platform. This routeis about 100m long and there are ticket checkinggates and descending steps on the way. We haveconfirmed that the user can arrive at the destina-tion by following the guide messages of the sys-tem. The mean time required to the destinationis 3 minutes and 58 seconds. The mean speed is0.57 m/sec when walking in the concourse. Weasked the participants who have the mental mapof the test area beforehand to walk along the sameroute in the concourse without using the system.The mean speed in this case is 0.60 m/sec. Inthe hearing session after the test, they said thatthe move by the guide of the system is satisfac-tory. However, examining the video recorded inthe test, five of ten participants sometimes wentpast the turning point one or two steps. We ex-pect that this phenomenon will disappear if theybecome more familiarized with the usage of thesystem.

2. Installation of the guide blocksThere is an expansion joint — joint position ofbuildings — in the concourse and it often confusedthe participants because they misunderstood thatit was a line of Braille blocks. The complicated in-stallation of blocks such as those near a toilet en-trance perplexed their walks. In order to use this

system more effectively, it is required to considerthe optimum installation method of the Brailleblock.

3. Arrangement of RF-ID tagsThe radio tags are embedded in intervals of lessthan 5 m along the straight line of Braille blocks.On the turning point, in order to guide themquickly, tags are embedded in the blocks adjacentto the turning point. Consequently, it was some-times observed that detecting the tag at the centerof turning point is difficult for the user who hasstopped at the turning point. So it is consideredthat tags should be embedded in the Braille blockpositioned at the center of the turning point.

4. Size and weight of mobile terminalNine of ten participants desired that the mobileterminal would be smaller and lighter. Five par-ticipants commented that the cane is heavy. Asthe current system is a trial product, it is designedwith a margin in the size and weight. So many ofthe participants were not satisfied with the cur-rent system contrary to our expectations.

5. Guidance levelThe system has two guidance levels, the detailedlevel and the simple level. At the detailed level,the system tells the user the distance to the desti-nation and the distance to the next right- or left-turning point. At the simple level, the systemomits the distance information, etc. We askedthe participants to compare the two guidance lev-els considering the user-friendliness. Although theopinion on which level they prefer differs from per-son to person, most comments can be summarizedas “I want to select either of them depending onthe situation whether I am familiar with the sta-tion or not.” Moreover, all participants estimatedthe function as “it is very good for users to be ableto select the guidance level according to their will,like with this system.”

6. Human interfaceIn order to evaluate the human interface of thesystem, we asked participants to operate the sys-tem by themselves. The operations they per-formed are setting destinations, selection of aguidance level and setup of a voice pitch of mes-sages offered by the system. As a consequence, wehave confirmed that even aged participants canuse the system without special training. In thehearing session after the test, they answered thatthe operation by using collar unit is satisfactory.As for the operation by voice, eight persons an-swered “it is easy,” but two persons commentedthat the performance of voice recognition is poor.In addition, a few persons commented that it is

Figure 10: Field test in an actual station

necessary to be able to sense more clearly how itworks when he/she operates the small volume dialattached to the mobile terminal.

7. Mental stress and resource for attention

In the test at the actual station, noise from the en-vironment, such as announcement, voice of otherpassengers and noise generated by trains, differsfrom that of the test field at the institute. In ad-dition, visually disabled persons get more stressescaused by the interference of other passengers andthe fear of the fall from a platform, etc. Since vi-sually disabled persons cannot depend on visualinformation like other passengers, they need topay attention to the aural information and thecontact information from their feet or canes to de-tect the difference in level or obstacles. We askedthe participants about their mental stresses andresource for attention. All of them answered thatit is possible to pay attention to the surroundingsand sense dangerous points. They also said thatthey could get information from this system easilyeven when a train was approaching.

8. Others

The points that many participants estimated asgood about the functions are as follows;

(a) Although there is a restriction that theymust use it only on Braille blocks, they canget the current location whenever they want.

(b) The system offers proper information toguide to the train door or stairs even on plat-forms. Moreover, if he/she misses the route,the system offers a message to correct theroute.

(c) The system gives the opportunity for them touse various equipment and utilities at largestations effectively as they can receive appro-priate information.

A past research in Japan, which investigated the dif-ficult tasks when a visually disabled person uses a rail-way without a care worker, reported the difficult tasksat a railway station are “purchase of tickets,” “moveto a platform” and “move on a platform.” Orientation— knowing the relative position between him/herselfand surroundings — is indispensable to the task aboutmoving. The reason why the task about “moving”is considered so difficult is that it is very difficult toget information about “orientation” if they cannot uti-lize visual information. We think that the participantsevaluated the system as (a) and (b) above, because theinformation about orientation is given by the systemeasily. As a common opinion, they told that “I wantto carry this system and use large stations alone evenif I am not familiar with the stations.”

9 Concluding remarks

In this paper we have introduced a new concept of pas-senger support system for the public transport systembased on information integration and dynamic person-alization in multi-channel data dissemination environ-ments. The prototype system for visually handicappedpassengers has been presented. There are many re-search issues to be resolved in future. These are radiocommunication method for multi-channel data dissem-ination, data organization of each channel, efficiencyand reliability analysis, effective personalization tech-nique, improvement and evaluation of the prototypesystem, implementation of intelligent software agents,good human interface and cost analysis etc. We willcontinue to research on these issues for implementingthe system in the real world.

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