Web GIS serving the intelligent Transport System
Modern technologies utilization particularly information technology development,
establishment of active networks, using computer systems in implementing operations,
and promotion of the culture of applying new technologies are amongst the
policies that the Iranian Transportation and Terminals Organization (ITTO)
affiliated to the Ministry of Roads and Transportation follows up since 1994
when the Ministry's title modified from Ministry of Roads to the Ministry of
Road and Transportation according to the law ratified by the Parliament in July
1994. The approval put more responsibility and functions on the Ministry in
controlling and management of routes and transportation issues. This is
basically in support of the 4th National
Master Plan of
Benefiting new technologies ITTO's Development,
Maintenance and Utilization Department of Roadway Network duly established a data
base about roadway situation, technical foundations and auxiliary installations.
The data base has been set up in such a way that could be easily up-dated for all
the necessary alterations, modifications and new developments. In order to reach
this goal through contribution of ITTO and Deputy for Roadway Maintenance and Provincial
Affairs Coordination of the Ministry of Road and Transportation, the roadway
identification and auxiliary installations plan was carried out.
In the mentioned plan, data gathering by using GPS connected to
qualitative computer geographic coordinates of roadway network based on roadway
type and specifications have been undertaken and for each 200 meter a spot was marked.
Also at the stage of field statistics, geographic coordinates of technical
foundations such as bridges, tunnels, water fronts, retaining walls,
intersection, etc. have been allocated and through specific forms metadata related
to technical foundations have been collected at Road and Transport Office
headquarters and added as the next data layer. Taking into account the
auxiliary installations including fuel supply stations, bascules, service
units, hygienic, telecommunications, service providing and technical services
in addition to geographic coordinates registration, all other information
required at field statistics stage was collected and added as extra data layers.
The objective of implementing the plan was to establish a data base
comprising of roadway identification and auxiliary installations in a GIS environment
by utilization of which and adding diversified data layers, statewide transport
officials would have access to appropriate tools for well managing maintenance,
construction and development of roadway network, organizing and streamlining
auxiliary installations, disseminating information to road users, locating
auxiliary installations, tourism and welfare service complexes and increasing safety
traffic index at roadways as well.
Development Procedure
To set up an
efficient Web GIS for ITTO several
strategies was proposed to enable the system planners to provide a favorable implementation.
The strategies were technically and knowledge-basely assessed and manipulated so
that the requirement of ITTO project could meet the
minimum cost and time. In the image 1 the Web GIS development hierarchy for
ITTO is shown. It is based on 8 major phases that starts with the requirement
analysis and concludes with the use and maintenance of the Web GIS system.
ITTO Web GIS project
aims at disseminating Iranian road information through the Internet for easy
data accessibility. The requirement analysis phase was performed carefully through
interviewing potential users. This phase produced two critical lists of
information that is:
1.
Needed functions;
the required functions are the basic visualization functions such as Pan, Zoom,
and more advanced functions such as object identification, spatial query, and
shortest path. Users are capable of applying these functions to view road
information, and peripheral constructions like gas stations and so on.
2.
Available
or needed geographic data; ITTO captured several layers of road information
using GPS. The project used only 25 layers of information including police
stations, restaurants, gas stations, mosques, etc.
The
information achieved through the requirement analysis phase was fed directly to
the next phase - Conceptual GIS Design.
Once the
required data identified the data model that describes the entities and their
relationships were designed. Since, the data is delivered through a central
server, and users have access to raster formats, Medium Client architecture was
chosen to provide users with access to interactive maps.
Selecting
suitable software was important for implementing the project successfully.
Software was evaluated on functionality and performance, and independent of the
hardware and operating system. Considering required functions, cost, and efficiency
ArcIMS 3.1, and MapObjects
IMS were selected for further evaluation. Web GIS requires specific hardware
configuration. Since the volume of transferred data is huge, the speed of
Internet connection is a key factor. Most of the data are sent from map server
to clients, that by the way the transmission speed has been identified to be
more than 128kbs. Based on a pilot project and the experience gained through
similar projects, a dual processor computer with 512 MB Ram was selected for the
project.
The primary
purpose of design and construction of database phase of the Web GIS development
process was to specify how the Web GIS performs the required applications.
Database design involved defining how graphics would be symbolized in terms of color,
weight, size, symbols, and so on, how graphics files would be structured, how
non graphic attribute files would be structured, what was the active layer, in
which scale should the layers be exposed, how GIS products would be presented based
on map sheet layouts, report formats, etc., and what management and security
restrictions required to be imposed on file access. Selecting a source (document, map, digital file, etc.)
for each entity and attribute, setting-up the actual database design (logical
or physical design), defining the procedures for converting data from source
media to the database, and defining procedures for managing and maintaining the
database were the respective functions that led to the project aim.
The database
design was conducted in parallel with the pilot study and benchmarking processes.
Actual procedures and the physical database design could not be completed until
a specific GIS hardware and software was selected while at the same time GIS
hardware and software selection cannot be finalized until the selected GIS can
be shown to adequately perform the required functions on the data. Therefore,
the three activities, design, testing, and hardware-software acquisition was
conducted concurrently and frequently.
At Web GIS
System Integration phase the Web GIS hardware and software was acquired and
data conversion was completed. The objective of this phase was then to
integrate different components of the hardware and software, to test them to
make sure they work as expected, and to initiate all procedures necessary to
use the GIS.
The initial requirement
analysis phase contained some applications of fairly complex nature. However,
the majority of initial applications was straightforward, and can be
implemented using the basic functionality that is part of the Web GIS software.
More complex applications were not supported by the basic functions of Web GIS
but have been programmed. Ease of use, user-friendliness, and reducing the data
transfer volume were the critical issues faced in the development. Image 2
shows the user interface that was developed using HTML, Java Script, and Java
as well.
The final phase
in implementing ITTO's Web GIS was to put the system
to use. In this phase user support and service as
well as system maintenance were taken into account and has been
programmed.
Web GIS system at work
Web GIS
development processes faces new challenges such as technology innovations, huge
data transfer rate, and the users who are not specializing in technology. Due to high data transfer rate from server to client, high
Internet band must be selected while it is the same for selecting processing
system with high effectiveness. It is the privilege of the system that the
users can access to road data with no time and place limitations. At the same
time, travelers can plan and manage their trip efficiently.
ITTO's Web GIS was designed and put at
work late in 2002 and is accessible through www.iranroads.com. It is a user friendly system
that works based on the functions including zoom in-out, pan, shortest path,
move, media, distance, selection and clear function. The information about the
provinces and their limits, structures, road types including freeways,
highways, main and secondary roads, rural roads, urban roads and transit roads
is available through the site both statically and graphically. Foundations like
clinics, mechanical stations, gas stations, telephone, welfare, police
stations, mosques, religious places, terminals and TIR-parks are available also
to users and can be located easily. The system has been set up in such the way
that potentially could be developed to support also the railway information in
the future.
ITTO's Web GIS and the services that it
provides for the variety of users by the net bring
Parviz Tarikhi is a space
science and technology expert, freelance journalist and technical writer based
in
______________________________
Image captions:
The caption for image 1 [WebGIScycle.jpg]:
Web GIS Development Hierarchy
(image source: ITTO)
The caption for image 2
[WebGIS1.jpg]:
The User
Interface (image source:
ITTO)
The caption for image 3
[WebGIS2.jpg]:
Zoom-in view of the Web GIS user
interface (image source:
ITTO)
The caption for image 4
[tto-headquarter.jpg]:
Headquarter building of ITTO
(image source: ITTO)
The caption for image 5
[Chalous-road.jpg]:
The caption for image 5
[Tehran.jpg]:
November 2006
