METHODOLOGY FOR ADVANCED TRAVELLER INFORMATION SYSTEM FOR DEVELOPING COUNTRIES

Abstract

National and regional state transport regulatory authorities in developing countries have been monitoring traffic and collecting traffic data (traffic stream volume, density, speed etc.) as part of their traffic management role for many years, but generally they did not share this information with the public. Furthermore due to spatial and temporal variations in traffic, roadway and weather conditions, travellers travelling within cities are not generally conversant with these prevailing conditions. Advanced Traveller Information Systems (ATIS) which are one of the areas of Intelligent Transportation System (ITS) aims at bridging this information gap by implementing computer, communication, information technologies and management strategies in order to provide the pretrip and/or en-route information to the travellers about their travel options (mode choice, time of travel and route choice). This research work focuses towards the development of amethodology for structurally storing and analysing the spatial (including associated attribute data) and temporal data and disseminating the value-added traveller information under prevailing road and traffic conditions in metropolitan cities in developing countries. Methodology involves (i) identification and selection of suitable logical architecture (ii) collection of relevant data (iii) database design and implementation (iv) selection of software and hardware (iv) formulation of workflows for carrying out geo-spatial and network analysis and (v) subsequently developing a web GIS based system based on selected architecture for traveller information dissemination. A Specific Design of Logical Architecture (SDLA) has been selected as a part of proposed methodology. SDLA is based on selected software, database design, relations between software components comprising of their in-between interaction in terms of data flow and information generation. Selected SDLA utilises the integration of two wellknown information technologies viz. World Wide Web (WWW) or web and Geographic Information Systems (GIS) and based on three-tier client server architecture. Three-tier architecture is a client-server architecture that logically partitions major functions into three tiers so that the presentation is independent of the processing rules and business logic, which in turn is separate from the data. These three-tiers are - (i) Presentation Tier (User Interface) (ii) Application Tier (Data Processing and Information Generation Rules) and (iii) Data Tier (for data storage and management). This architecture greatly reduces maintenance costs and increases functional flexibility in the long run. WWW provides a cost effective means to disseminate useful geographically referenced information to a large number of travellers without burdening them with complicated and expensive technology so that they can be accessed data across a network, from any location. GIS enhances the information dissemination capabilities of ATIS and enables it to generate the graphical (map) based information dynamically as per user request and it provides the necessary functions for carrying out geo-spatial analysis on the geographical referenced features and road network and transit data. Various kinds of data have been acquired for information generation viz. (i) Spatial and associated attribute data pertaining to road network, (ii) Spatial and associated attribute data of roadside features or Points of Interest (POI) e.g. hotels, offices, historical places etc. (iii) Tabular data about traffic stream (volume, travel time, speed) for each lane of roads in the road network, (iv) Tabular data about incident conditions like accidents, construction zones, heavy congestion zones etc. and (v) Transit Data viz. spatial data about bus stops and tabular data pertaining to bus routes. Database relationships have been formulated to structurally organize the data for better data processing and query performance. Geomedia Professional GIS Software has been used for acquiring map based spatial information. Non-spatial information have acquired for other sources. Subsequently acquired data are stored in a RDBMS namely SQL Server 2000 as per formulated relationships. SQL Server 2000 is a full-featured relational database management system (RDBMS) developed by Microsoft Corporation that offers a variety of administrative tools to speed up database development, maintenance and administration. Subsequently a Web GIS based ATIS has been developed as part of methodology development. This ATIS is named as Computerized Traveller Information and Decision Support System (CTIDSS). CTIDSS is based on (i) selected SDLA, (ii) formulated database design and selected data and (iii) implementation of formulated workflows using scripting programs for information generation and dissemination. Development has been carried out in iterative and incremental way that allows the developer to take advantage of what was being learned during the development of earlier versions of the system. CTIDSS provides a standard, interactive, user-friendly and intuitive graphical interface to access useful traveller information from different sources. CTIDSS comprises of five basic modules, each one ofthem consisting ofseveral functionalities. These five modules are: (i) Search Module for dissemination of yellow pages information about the road side features, (ii) Traffic/Road Info Module for dissemination of information about traffic stream and road side incidents, (iii) Network Analysis Module for dissemination of information based on network analysis, (iv) Transit Module for disseminating information about buses and (v) Data Update Module for authorised updating oftraffic stream and incident data. Proposed SDLA, selected data and its implementation, formulated database design development guidelines, and CTIDSS combines to form an integrated methodology, which is geographically transferable, and can be used for development of ATIS for developing countries. in