International Road Assessment Program (iRAP): Enhancement Using GIS Analysis

International Road Assessment Program (iRAP): Enhancement Using GIS Analysis

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Azzuhana Roslan, Nusayba MJ, Sharifah Allyana SMR

Researcher, Road Safety Engineering and Environment Research Centre (REER) at Malaysian Institute of Road Safety Research (MIROS)

A risk map highlights areas that are affected by, or vulnerable to, a particular hazard. Risk maps help road concessionaires to take some preventive measures on their roads. It is a process that uses existing data, including detailed crash and traffic data, to depict an objective view of where people are being killed or seriously injured on the road. It also enables an overview of where crash risk is greatest within a road network. Risk mapping is used to identify sections of road that are high-risk, rather than depicting just point or cluster locations of crashes (such as blackspots). This paper addresses risk mapping methods and geographic information (GIS) technique adopted in producing a risk map for the Malaysian road network and highlighting the challenges in developing techniques and using the right tools.

Road crashes cost approximately 1 to 3 percent of a country's annual Gross National Product (GNP). These are resources that no country can afford to lose, especially those with developing economies. It is estimated that developing countries currently lose in the region of $100 billion every year. This is almost twice as much as the total development assistance received worldwide by the developing countries. These losses undoubtedly inhibit the economic and social development of developing countries.

Even though it might be useful approach to plan for better future road network, improvement performance of existing road network also must be done for better road safety. Identify highly risk road network helped in plan for improve road safety.

International Road Assessment Programme (iRAP) is a registered charity dedicated to preventing the more than 3,500 road deaths that occur every day worldwide with vision a world free of high risk roads. iRAP works in partnership with government and non-government organisations to inspect high-risk roads and develop Star Ratings and Safer Roads Investment Plans. They also provide training, technology and support that will build and sustain national, regional and local capability and track road safety performance so that funding agencies can assess the benefits of their investments. iRAP aims to significantly reduce road casualties by improving the safety of road infrastructure.

In 2006 and 2007 four pilot studies in Malaysia, Chile, Costa Rica and South Africa have been undertaken. These studies showed that road assessment is also helpful in developing countries. High-risk roads where large numbers are killed or seriously injured are inspected and affordable programmes of safety engineering are identified. As the percentage of vulnerable road users, like pedestrians and two-wheelers among the road deaths is high in those countries, iRAP focuses on measures to improve road design especially for these users.

Risk maps help road concessionaires to take some preventive measures on their roads. It is a process that uses existing data, including detailed crash and traffic data, to depict an objective view of where people are being killed or seriously injured on the road. It also enables an overview of where crash risk is greatest within a road network. Risk mapping is used to identify sections of road that are high-risk, rather than depicting just point or cluster locations of crashes (such as black spots). Road sections are placed into colour-coded categories rated from high-risk to low-risk. Reliable and detailed data help road safety practitioners accurately identify problems, risk factors and priority areas, and to formulate strategy, set targets and monitor performance as shown in Figure 1.

Define Problems > Identify Risk Factors > priorities > Formulate Strategies > Set Target and Monitor Performance

Figure 1: Data flow Road Safety Management flow

Dataset Preparation

In order to correctly identify problems and monitor performance, reliable and accurate data are needed at each stage of road safety management. Data is the cornerstone of all road safety activity and is essential for the diagnosis of the road crash problem and for monitoring road safety efforts. Relevant data are collected every day, but for these data to be useful for informing road safety practice, they must be properly coded and visualized, processed and analysed in a systematic way.

Nowadays GIS has been widely used for the geocoding of accident locations and developing maps of crashes. GIS also been used to give more information thru visual representation with integration different data types.

This study focused on selected federal road in Malaysia. Digital road network data will used in this study to determine the risk segment. Traffic volume and composition were obtained from the Public Works Department and Highway Planning Unit, Ministry of Works Malaysia.

The number of fatal and serious road crashes data in this study is obtained from Royale Malaysian Police (PDRM) and analysed by MIROS Roads Accident Database System (MROADS). The data consists of the details of latitude and longitude (locations) fatal and serious crashes occurring on federal road for year 2009 until 2011.

This study use open source software such as google earth to determine number of lane and type of carriageway. This study also considers rural and urban areas to standardize the segmentation. All data finally will be recorded using iRAP special form to identify the risk segment class.

iRAP Risk Mapping

Risk mapping is used to identify sections of road that are high-risk, rather than depicting just point or cluster locations of crashes (such as black spots). Road sections are placed into colour-coded categories rated from high-risk to low-risk. They capture the combined risk arising from the interaction of road users, vehicle and environment.

Segmentation and Risk Calculation

They have several variables need to be considered in determine the risk segment. Using the latitude and longitude of the location, road crashes data will be plot using open source software which is for this studying using google earth. This is used to identify the number of road lane, type of road carriageway and crashes area types.

Result show over 50% of fatal crashes fatal crashes on 2009 to 2012 occurs at rural area. In this study, it is important to consider area (rural or urban) of the segmentation.

Geospatial data or geographic information it is the data or information that identifies the geographic location of features and boundaries on Earth, such as natural or constructed features, oceans, and more. Spatial data is usually stored as coordinates and topology, and is data that can be mapped.

In this study, information or geocoding of road crashes locations is a main variable to determine the stretch segment. Determination of road segment is based on either 20 numbers of crashes or a stretch of 10km road length. However, the length of segment will be extending if it is covered mix of area types (urban/rural). Latitude and longitude start and end point of this segment point will be recorded (Figure 3). Based on the start and end point of segments, other variable such as number of lane, type of carriageway will be determined. Road traffic volume were obtained from traffic volume station base on segmentize stretch.

Figure 3: Data used in risk calculation

Risk calculations are tabulated using iRAP Risk Mapping form (Figure 4). The data which has been tabulated will be fill in iRAP form and risk class obtained based on formula calculation.

Figure 4: iRAP Risk Mapping calculation form

ArcGIS Mapping

ArcGIS used in this study to develop risk mapping which show stretch of road risk. Layer base on road number were created using variable which is calculated earlier. These data will overlay with road network and other relevance data such as states boundaries. Two main tools in ArcGIS used in this study (Figure 5). Using the split tool command in ArcGIS, the road data is split based on start and end point of segment. Graduate colour (Table 1) on layer properties is used to show risk class ranges

Figure 5: Split Tool and Layer Properties

Colour

Risk Segment Class

Black

High Risk

Red

Medium-High Risk

Yellow

Medium Risk

Light Yellow

Low-Medium Risk

Green

Low Risk

Table 1: Risk Segment Class

iRAP, was introduced in Malaysia to give star rating for federal roads and highways. For this study, selected roads were assessed according to their engineering attributes such as number of lanes, type of road carriageway, and traffic volume.

Figure 6 show iRAP risk mapping which has been produced using ArcGIS. Risk mapping show the area with road segment with highly risk (segment colour in black) which required immediately attention and low risk (segment colour in green) which should be managed by routine procedures.

Risk maps help road concessionaires and local authorities to take some preventive measures on their roads. Furthermore it is a process that uses existing data, including detailed crash and traffic data, to depict an objective view of where people are being killed or seriously injured on the road.

Data is the cornerstone of all road safety activity and is essential for the diagnosis of the road crash problem and for monitoring road safety. However, the reliable and accuracy of data play main role in identify the risk.

GIS is useful in identifies the geographic location of features. Spatial data is usually stored as coordinates and topology, and is data that can be mapped.

In this study, information or geocoding of road crashes locations is a main variable to determine the stretch segment. However, availability of data and lack of road crashes location information contribute the limitations to control the accuracy of this study.

Figure 6: iRAP Risk Mapping