STUDY METHODOLOGY

3.1            INTRODUCTION

Methodology is the usage of simplified methods or techniques for achieving the formulated objectives. In this chapter the stages involved in the study with the flow chart is given in fig 3.1. Various data required for the study and the process involved in the collection are also discussed. The development of web based accident analysis system is explained as separate in chapter 4.

3.2            METHODOLOGY 

                                 Fig 3.1. Methodology Flow Chart

            It has been planned to have the system to be accessed by user agencies through WAN (Wide Area Network). Fig 3.2 shows that network configuration for the proposed web based Accident Analysis System. In this system, several remote sites shall be connected in a WAN.  A cost- effective network connection can be established using dial-up network protocols. A central site shall maintain the database and map server.

            In a system, information from the traffic accident investigation report forms is directly encoded via an interface program. The application shall be constructed under client/server architecture. Reporting police stations shall only need to forward their reports to the concerned office for proper processing and input. The system shall also update the master database at the central site.

     Central to the system is the utilization of GIS technology. Utilization of such a cost-effective technology offers big potential for information delivery. Fig 3.3 Components of Web GIS based Accident Analysis System. The use of geo-referencing accident data. Proper and accurate spot maps can be established. Moreover, accident data can be tied with other spatial data such as road characteristic and intersection geometry, to cover a full- range of analysis.

                   Fig 3.3 System Component flow Chart

Spatial data has to be linked to accident data to provide the graphical interface to search for accident frequencies with varying spatial units, such as intersections and highway segments. To reduce accident frequencies, it is imperative to investigate the contributing factors at a disaggregated level

3.1            STUDY AREA

The area for application of developed system is an Adyar Taluk (Urban area) and East Cost Road between Uthandi and Kizputtupattu village (rural road stretch). The road stretch starts at km 20/000 and ends at km 135/000.

East Cost Road is selected to study the accident occurrence on Highway when it leads to an Urban Area shown in fig 3.6.

3.3.1    Adyar

The Adyar area is in southern part of the Chennai which is snow in Fig3.4 and Fig 3.5 shows detailed road network of Adyar Taluk map. Latitude extends from 12.98 to 13. 03 and Longitude extends from 80.22 to 80.28. Total Area covers approximately 46 Sq. km and total length of the road in Adyar Taluk choosen for the study is 211.507 km.

Fig 3.4 Chennai map showing the study area (Adyar Taluk) location




Fig 3.5 Detailed road network map of Adyar Taluk

3.3.2       East Cost Road

            East Cost Road starts from the Adyar Taluk which connects Chennai, Mamallapuram, Kalpakkam, Pondicherry and Cuddalore. The road was constructed by Government of Tamilnadu under Asian Development Bank Funding and being maintained by Tamil Nadu Road Development Company (TNRDC). Accident data for ECR was Collected from TNRDC.

            The East Cost Road is a compromise on both environmental and safety factors. In this project stretch from Uthandi (21/000 Km) to Kizputtupattu Village (135/000 Km) has been considered.

3.4.1    COLLECTION OF ACCIDENT DATA

     Accident data for Adyar area was collected from DGP Office and East Cost Road Data from TNRDC for the year 2004 to 2006. A Sample of data collected is shown in table 3.2.

Table.3.2 Sample Data Format

3.4.2       COLLECTION OF PRIMARY DATA

Latitude and Longitude for each accident location was collected and database was prepared. Other data like Hospital location, important landmark in the study area were collected and used in preparation of thematic map.

Table 3.3 Name of Hospital in Adyar Taluk

3.4     PRESENTATION OF DATA

3.5.1       ADYAR

Accident data for Adyar Taluk was collected from DGP office and presented below. Fig 3.7 shows accident trend in Adyar Taluk. Fig 3.8 type of accident Adyer Thaluk. Accidents occurrence in 2005 declined when compare to 2004. In 2006 there was marginal increase.

Table 3.5 Major Towns & Villages

Source – TNRDC

Of the above towns, Mamallapuram and Marakkanam have bypasses already constructed as a part of the ECR Project. The ECR stretch has several tourist attraction centers including Amusement parks, Boat clubs, Centre for Herpetology, Beach resorts etc.,. The details of the Centers are given below.

Table 3.6 Tourist spots along ECR Between Chennai & Cuddalore

Source: TNRDC

         

Fig 3.11 Accident Trend on East Cost Road

Fig3.12 Month  wise Accident occurrence on East Cost Road (2003-2006)

Fig 3.12 shows month wise accident occurrence on East Cost Road. During August, most of the accidents are due to Negligent driving and Over speeding. 11 accidents due to Skidding, 9 Head on Collision and 4 Hit & Run cases and the rest are collision between vehicles ( Car hit TW or Pedestrian)

Fig3.13 Month wise Fatal Accident occurrence on East Cost Road (2003-2006)

 Fig3.13 shows month wise fatal accident occurrence on east cost road (2003- 2006).Number of Fatal accidents during accidents gradually increases for the past 3 years.

Fig3.14 Day wise Accident occurrence on East Cost Road (2003-2006)

Fig3.14 shows day wise accident occurrence on East Cost Road. Weekend days are more accident prone on ECR when compare to week days (Monday to Friday)

 Fig3.15 Time wise Accident occurrence on East Cost Road

Fig 3.15 shows time wise accident occurrence on East Cost Road. The Number of accidents is found to be more during 19:00 – 20:00 Hours. Fig 3.16 shows time wise fatal accident occurrence on East Cost Road.  The Number of Fatal accidents is found to be more during 5:00 – 6:00(5), 14:00 – 15:00 (6), 18:00 – 21:00 (6) is shown in fig 3.16

Fig3.16 Time wise Fatal Accident occurrence on East Cost Road

3.6 DIGITISATION OF ROAD NETWORK AND PREPARATION OF THE DATA BASE

3.6.1 DIGITISING THE MAP

          Thematic map are prepared using MapInfo and Arcview3.2a software. Thematic map are spatial date, which will be in any one of the form of spatial entities like point, Line or polygon. All the thematic maps are in Lat/1Long as a coordinate system and WGS84 as a reference datum. The thematic maps are

Ø     Road Network map

Ø     Accident Location Map

Ø     Hospital Location Map

Ø     Important Landmark Map

              MapInfo software used to digitize Road Network map for Adyar and East Cost. Thematic map for accident locations, Landmark Location, Hospital Location are Created using Latitude and Longitude collected in primary data.

             Topology is important parameter, which establishes the relationship between the spatial entities. Topology is created using Arcgis9.1 software fig3.16 shows the Road network map with accident location for Adyar Taluk.

Fig 3.17.Road Network  map with Accident location

3.6.2 PREPARATION OF DATABASE

          The ability of GIS software is linking spatial data with its attributes and performing the analysis based on the attribute date. It is easily understandable when the attributes are represented with its spatial Databases are prepared for each thematic map.

Ø     Road network database contains attributes like ID, Latitude, longitude, From Node, To Node, One Way, and Length for each segment.

Ø     Accident database contains consist attributes like ID, Latitude, longitude, Date of accident, Day, Month ,Year, Time, Type of vehicle involved,Type of accident, Number of accident, Number  of people involved, Reasons for accident, Landuse at the accident location, Nearest landmark.

Ø     Hospital database contains consist of name of hospital and coordinate of the location.

Ø     Landmark database contains contain name of the landmark and its latitude and longitude.