Web-Based Interaction

The web is a suitable medium for delivering transit information: it has the potential to reach a large audience with transit information at a low cost. Transit information can also be accessed at any time. The Web interface is ideal for quickly retrieving information; however, it needs more attention in terms of design. Interface design concerns are related to the presentation and interaction of the data to the end-user. For real-time transit vehicle systems, the user interface should enable complete navigation of the transit region map via a variety of interactive gestures and tools. Features including arrival time prediction information, alarm notifications for selectable bus stop and searching for a particular bus stop, transit vehicle or point of interest are valuable tools in allowing passengers to make better travel decisions (Stuart D. M. and Daniel J. D., 2001).

Map-based representations of transit data assist in understanding and visualising of transportation information. Map-based representations combined with web service technologies such as AJAX (Zepeda J.S. and Chapa,S.V. 2007) are particularly well suited to real-time updates. The user is not required to interact with the map interfaces to retrieve updates: these updates to the map content can happen automatically on the browser. Icons on a map can be used to represent vehicles and these icons can move automatically, with no action required by the user, representing the last-known locations of a vehicle.

The proliferation of web map Application Programming Interfaces (API), such as OpenStreetMap (OpenStreetMap, 2012), Google Maps (Google Maps, 2012) and Bing Maps (Bing Maps, 2012) allows developers to overlay and combine data from different sources and make it appear on top of interactive maps. This can be useful to application developers for developing real-time transit information systems allowing transit data such as bus routes, bus stop locations and transit vehicles’ current locations to be shown on a map.

Figure (5-2) shows the architecture of a web-based display of a real-time vehicle tracking system. In Figure (5-2) the web interface may involve XHTML, Cascading

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Style Sheets (CSS) and a Document Object Model (DOM). The XHTML has the content of the page through tags. CSS offers the separation of content and presentation in the page through style documents with the elimination of redundancy. The CSS rules are in different files to achieve the separation. The DOM specification contains the way of dynamic access and the updating of the content, structure, style, and elements of a page. The application sends a request to change the content, and depending on the browser the request the applications creates is sent. For example, Internet explorer uses a special class called ActiveXObjetc, while Firefox and Safari use the XMLHttpRequest object.

Figure 5-2 The real-time web-based display of a vehicle tracking system for internet explorer only

The request is sent through the HTTP protocol and processed at the server-side. The database returns new data to the web from the application, using a combination of the the DOM and CSS the new data is added and the web interface updated. Public transport systems such as BusView (Stuart D. M. and Daniel J. D., 2001), OneBusAway (B. Ferris., Kari, W. and Alan, B. 2010), NextBus (NextBus, 2012) offer web-based user interaction for their passengers to interact with the transport system.

In our public transport software system, we have developed a public interface whose primary view is a Bing map from Microsoft, which shows and updates vehicle

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locations in a close to real-time environment. Passengers can browse the map directly to see transit stops at a particular location. Passengers can switch between bus routes and display transit vehicles for each route. We calculate the direction of travel for buses and show a directional arrow for the vehicle on the map. This direction-of-travel-arrow is particularly useful to passengers for differentiating between transit vehicles. Figures (5-3) and (5-4) show the public interfaces of transport system.

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Figure 5-4 Public passenger interface to transport system shows a variety of transport services

As we can see in Figure (5-3) and (5-4), the user interface has been divided into parts and the user can navigate between them easily. The first tab menu in Figure 5-3 displays the bus data of bus route No. 5, while the second tab menu displays the bus data of a different bus route. This is to show the system's ability to manage and organize more than one bus route. As for the other two tabs in Figure 5-3, they offer the user a variety of tools to find information. Through the user interface, passengers can access real-time transit information, display and review information for a particular bus. Passengers can search by bus route to display the map of that route, and the stops along the route, as shown in Figure (5-5).

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Figure 5-5 Transit stops along Blackpool Route 5

Our system provides a next bus service where passengers select a particular bus stop to enquire about upcoming vehicles. The system will also show transit vehicles and estimated times of arrival. As shown in Figure (5-6), a list of bus stops and next bus service is illustrated.

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Figure 5-6 Upcoming transit vehicles to selected bus stop is shown

In addition, through the user interface, users can search for a particular bus stop or transit vehicle on the map, and subsequently the location of the bus stop or the current location of the vehicle is shown on the map with associated transit information. As we can see in Figure (5-7), transit vehicle no 252 is selected and its transit information is shown.

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Figure 5-7 Transit vehicle detailed information

In a similar way, as shown in Figure (5-8), the location of a bus stop is shown on a map with a detailed information window indicating the upcoming bus and the expected arrival time.

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Figure 5-8 Web interface, showing a transit stop on Route 5, with detailed information

For more services, the transport system provides passengers with a service to search for a particular Point of Interest or landmark on the transit map and access information such as the nearby bus stops together with the associated transit information. Figure (5-9) shows the Blackpool tower and the nearby bus stops and associated transit information.

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Figure 5-9 A point of interest and the associated transit information is shown on a map

Passengers can access timetable information using a particular bus route or bus stop. Figure (5-10) shows timetable information for bus stop no 41.

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Figure 5-10 Access timetable information

For any bus route and real-time progress of the transit vehicles on the route, passengers can see the progress through an alternative graphical view that displays the current location of vehicles along a particular bus route. Figure (5-11) shows the bus progress along the bus route. Vehicles location and estimated arrival times are updated on this view as new data is obtained.

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Figure 5-11 Route Progress View

To avoid lengthy waits at bus stops, passengers can set an alarm to notify them when a transit vehicle is within a predefined walkable distance. The alarm will automatically notify the passenger via a browser alert. For example, in Figure (5-12), the alarm notification is adjusted to five minutes before a transit vehicle arrival at the selected bus stop or station, (Market Street M13). When the bus is at a distance of 5 minutes the alarm alerts the passenger by showing a message on the screen. This can

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help to save passengers time, so they can spend their time productively on other activities near the transit stop.

Figure 5-12 Setting an alarm notification by selecting the time and bus stop of interest

Additionally, the system utilizes schedules or/and actual vehicle location reports and provides air terminal styled arrival/departure status. Passengers can access vehicle arrival/departure times for all bus stops. This can help passengers to track particular transit vehicles while they are in service. Figure (5-13) shows the last known position of a bus and bus arrival times in minutes to the bus terminus, along with real-time location on the transit map. This service can be accessed through the “Bus arrival times” option on the user interface.

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Figure 5-13 Bus arrival times in tabular format

A trip planner service is available for passengers to plan their trip in advance and obtain pre-trip information. This tool, as we will discuss in Chapter 6, integrates real- time transit information with pedestrian navigation systems to provide passengers with door-to-door journey planning information, utilizing real-time transit information instead of static timetables.