Effect of Wind Induced on Road Accident along East Coast Expressway (ECE)

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1 Effect of Wind Induced on Road Accident along East Coast Expressway (ECE) 1* Parameswary Sundara, 2 Nurul Nadrah Aqilah binti Tukimat, 3 Mohamad Idris bin Ali, 4 Norain binti Md Yusof 1*, 2, 3 Senior Lecturer, Faculty of Civil Engineering & Earth Resources, Universiti Malaysia Pahang, Gambang Pahang, Malaysia 4 Student, Faculty of Civil Engineering & Earth Resources, Universiti Malaysia Pahang Gambang Pahang, Malaysia Abstract The impact of cross wind speed depends on the roughness of Land Use and Land Cover (LULC), terrain and topography. Often the impacts of cross wind speed on traffic accidents are taken for granted and not incorporated into the road safety. It is a common knowledge that wind speed may induce road accident. Cross wind phenomena are broadly applied to all condition and are prevalent on some highway segments on the variation of topographic premises that wind drag effects promotes responsive driver behaviour and enhances alertness. Wind has an adverse effect on vision especially when wind blows obstacles such as debris and sand onto the road. The presence of obstacles has significant impact on the wind speed and alters the wind direction and thus will make situation more disorienting for drivers. Based on the synthesis aggregate of wind speed and terrain by mapping out specific areas where action is needed to access possibility of the accident prone location, wind impact study was carried out for an uninterrupted traffic flow on east coastal expressway. It is notable that the main focus of the research is to predict the changes of crosswind effect along the terrain of East Coast Expressway (ECE) and to warn road users to make better travelling on the expressway. With regard to that, GIS technique was used to establish database of study area, analysed effect of topographic variation in slope and the future wind pattern adapt to terrain change was determined. The survey data is supplemented with digital elevation model, one of the raster for GIS layer which was provided by Jabatan Ukur dan Pemetaan Malaysia (JUPEM) and ancillary accident data statistic along ECE was provided by Kuantan police traffic and Lembaga Lebuhraya Malaysia (LLM). Result shows that various characteristic of wind, slope and contour of topography affect the wind speed analysis. The scenario resembles that crosswind speed values are increased with the slope values where result shows that at KM133 with high slope o, the crosswind speed was depicted as 35km/hr which has exceeded from the safe crosswind of 15km/hr. One plausible reason is that variation in level of height distraction lead for a significant experiencing in wind speed. The study concluded that wind speed has the potential to trigger accidents of which has significant effect on road safety. The findings in this study can be incorporated into wider strategy for dynamic traffic management as it is very beneficial for the decision makers and authorities to monitor the effect of wind induced accidents along coastal expressway and propose adapting for a long term solution. Keywords: Wind Speed, Terrain, ECE, Accident, GIS. INTRODUCTION Highway is one of the infrastructure which will catalyst the economic and growth to any country. For this reason, government take an effort to construct highway for the country to give better commute. Construction of highway from one point to another point is inevitable as it has variation of terrain along the segment and thus has the potential to give effect of cross wind to passing vehicles. The design of highway according to the terrain should meet convenient and safety to road users. Adversely, occurrence of fatal accident give local authority concern regarding on highway safety. Obviously argument will arise within different party regarding on causes of accident. Eventually some authority has found that the lack of user altitude much contribute to the induced of road accident. (Norain, 2012). Very seldom decision maker take into account the cross wind effect as one of the contributor to the accident. Based on the synthesis aggregate of wind speed and terrain by mapping out specific areas where action is needed to access possibility of the accident prone location, this study has been carried out typical analysis of cross wind effect. Study of location has been covered entirely along the east coastal expressway (ECE) Malaysia. ECE was selected as the main research of this study because it is representing the most variation in topographic effect along the highway. BACKGROUND LITERATURE REVIEW Incorporating Cross Wind Speed along Terrain Wind speeds can be increased considerably by natural and man-made topography in the form of escarpments, embankments, ridges, cliffs and hills. The effect of wind speed is subjected to an extensive research in the 1970s and 1980s with the incentive to exploit wind power and to optimize the sitting of wind turbines. This work has improved greatly with the prediction of wind speeds over shallow topography. When wind approaches a shallow features, its speed reduces slightly as it encounters the start of the upwards slope. It then gradually increases in speed as it flows up the slope towards the crest. The maximum wind speed occurs at the crest or slightly upwind of it (Holmes, 2001). Wind is composed of a multitude of eddies of varying sizes and rotational characteristics carried along in a general stream of air moving relative to the earth's surface. These eddies give wind its gusty or turbulent character. The gustiness of strong winds in the lower levels of the atmosphere largely arises from interaction with surface features. The average wind speed over a time period of the order of ten minutes or more 8858

tends to increase with height while the gustiness tends to decrease with height (S.K Najid, 2008). The wind is defined in terms of a vector of its direction and speed.

The wind is said to have a crosswind component; that is it can be separated into two components, a crosswind component and a headwind or tailwind component.

2 tends to increase with height while the gustiness tends to decrease with height (S.K Najid, 2008). The wind is defined in terms of a vector of its direction and speed. The continuous wind measurements are taken as per international agreement (World Meteorological Organization, 1983) at fixed least disturbed stations at a height of 10m above the ground. The wind is said to have a crosswind component; that is it can be separated into two components, a crosswind component and a headwind or tailwind component. A crosswind is defined as any wind that has a perpendicular component to the line or direction of travel. Sometimes there will be winds which are not parallel against the line of travel (Chaw, 2006). With significant wind speed will make the situation more disorienting for drivers. The gust of air can be further amplified by the mountainous terrain (barrier jet or katabatic wind) and therefore will increase the possibility of strong crosswind to happen (Husdal J., 2000). The design speeds shall be adopted for various terrain classifications. Terrain is normally classified by the general slope of the ground across highway alignment (Klaus and Saren, 1983). The collective effect of the terrain surface and obstacles leading to an overall retarding of the wind near the ground is called as the roughness of the terrain. Orographic elements such as hills, cliffs, ridges and escarpments exert an additional influence to the wind. Studies have found that roughness and orography are among the main factors that affect the wind speed (Klaus and Saren, 1983). Theoretical Background of Wind Induce Accident Studies at terrain sections on the freeway are few in number. The recently studies are focus on the comparison with existing Topological Effect Model (TEM). TEM is developed to represent the wind speed effects by topology. The TEM is developed for 8 directions to consider non-homogenous topology to fetch upwind. The 30m resolution of TEM and Korean Building Code Structural are used to predict topographic factor in the area of operations where slope is defined as in the equation (1), (Young-Kyu Lee et. al., 2009). ϕ = H/2L h (1) Where: ϕ = upwind slope of the topographic features H = height of hill or escarpment relative to upwind terrain L h = distance upwind of crest Other studies are presentation of the methodology by revision in analyzing the relationship of wind flows over the earth surface under the variation of roughness of the terrain as in the equation (2) below: U(z) = U(zr)(z/zr) a (2) Where: U(z) = wind speed as a function of height, m/s U(zr) = wind speed at reference height, m/s z = height above ground, m zr = referenced height, m a = exponent dependent upon roughness of terrain This study is using the model analysis that has discussed and predicted the relationship of wind speed with slope in degree due to slope factor of freeway terrain sections. The study is focusing on the critical area for highest slope correlate with wind speed along east coastal highway. Second, it compares the result with accident prone area along the east coastal highway. The main cause of accidents is a progressive withdrawal of attention to traffic and the roadway environment which leads to impaired performance behind the wheel (Seungkirl Baek et al., 2005). It is proven where according to (Eckhardt, N. and Thomas I., 2004) have concluded that the characteristic of the environment and the roads significantly influence the occurrence of road accidents. The change on terrain is quite important elements in the explanation leading to the suggestion that road users do not adapt their behavior sufficiently to sudden changes in wind speed as shown in Figure 1.0. It indicates accident happened at Temerloh, ECE KM214.9 on 27 th September 2011 where during that period source from weather Wunderground.com has reported wind speed on 27 th September 2011 was 20km/hr compared with the other consistent wind speed and thus sudden increase in wind speed has induced road accident. In this study, measured wind data at the time of accident along with the description of road surface condition from police accident reports allow in depth analysis of accidents. Previous study has documented that the highest wind gust can be as high as 2.5 times higher than mean wind speed, frequently catching driver s off-guard despite variable message signs indicating the wind speed at the site (Thordasan, 2000). Accidents from crosswind can be classified into three types as shown in Figure 2.0. First type, a vehicle is blown over, in the second type a vehicle is blown a significance distance to sideways and in the third kind a vehicle is rotating through a significant angle around its vertical axis. Figure 1: Wind Speed and Wind Direction have induced accident at Temerloh, ECE KM214.9 on 27 th September 2011 Figure 2: Types of crosswind induce accident 8859

DATA COLLECTION Data was collected along the East Coastal Expressway (ECE). ECE is the only four-lane two-way highway linking from the west and to the east coast of Peninsular Malaysia.

3 DATA COLLECTION Data was collected along the East Coastal Expressway (ECE). ECE is the only four-lane two-way highway linking from the west and to the east coast of Peninsular Malaysia. ECE constructed in two phases. Phase 1 linking from Karak to Kuantan. Phase 2 is connecting from Kuantan to Kuala Terengganu. Phase 1 along the 169 km begins from Karak, Pahang (cross Karak) and ends at the borders of Pahang/Terengganu (cross) Kuantan. It is the connection from Kuala Lumpur to Karak present. The main concept of this highway construction was constructed as environmental friendly atmosphere under 'Environmental Management Program (EMP)'. Located at the east coast of Malaysia, the data sets consist of daily wind speed measured in meter per second. This is hourly wind speed and direction which includes sheltering obstacles, surface roughness changes and orographic data (terrain height). Local terrain at the site can caused the wind speed to vary seasonally because of differences in large scale of weather patterns. Wind from one direction may experience an increase in speed because of the hills nearby and may experience a decrease from another direction. Since wind is also the cause of copious rain in the country, terrain also likely to experience rain and high wind at the same time e.g storm. The topography of Malaysian land is largely mountainous and therefore some of the road networks are inevitability being constructed across the hilly areas. way. The weather pattern in Malaysia follows the South-East Asia monsoon wind system which produces the monsoon and the equatorial rain forest climate. ECE was investigated. Database for ECE was established using GIS technique. Series of data over study area which includes satellite image map, district map and contour map were converted into GIS base map. ECE map and location of road accident were derived from this base map. Slope variation map is used to deliver as contour map. Figure 3.0 shows result of slope variation image using GIS technique. SETUP IMPACT OF STUDY Primary data includes Satellite Image Capture from google earth and Digital Elevation Model (DEM) was collected. DEM is one of the types for raster image particularly being used in GIS layer. Raster GIS able to represents the study area as a regular arrangement of location. In DEM, each cell has a value corresponding to its elevation. Historical data was obtained from Jabatan Ukur dan Pemetaan Malaysia (JUPEM). Ancillary data consist of accident statistic along East Cost Malaysia (ECE) was collected. It determines the accident statistic according to kilometer in five years starting from 2007 until 2011 along study area. The accident statistic was obtained from Lembaga Lebuhraya Malaysia (LLM) and also from Kuantan police traffic to make for better comparison. Apart from that geographical information system (GIS) was used to coordinate the system which allows exploring and analysing the entire spatial of data. Identically ArcView GIS model was used in this study for applications in mapping so that it gives the power to visualize, explore, query and analyse data geographically in more appropriate way. In short, GIS technique was used in this study to establish terrain database along the study area. Location of accident prone area subjected to cross wind effect was determined using ECE mapping. Figure 3: Result of Slope Variation Image using GIS Technique Drivers response to change in crosswind speed depends on the slope variation along the ECE. Sensivity of the lead driver at the onset of wind speed and terrain changes are important determinants of slope topographic factor. This factor contributes to the phenomena and location of prone accident along ECE was determined. Figure 4.0 displays calculated crosswind speed value base on slope topographic factor. At the benchmark KM133 of ECE, it has highest slope o contributes to 35km/hr of crosswind speed which has exceeded the rate of safe crosswind speed 15km/hr. Result shows that crosswind speed value increase with the slope value suggesting that drivers are constrained by wind speed condition hence cannot choose to drive in high speed. This is because slope factor is a distractive condition which could lead to poor visibility in narrow curvature of road and thus could reduce the quality of driving subsequent of crosswind observable effect in relation with the slope variation along the highway. FINDINGS AND DISCUSSION There are a total of 772 km in length for North South Expressway (NSE) in west coast of Peninsula Malaysia and about 358 km in length for East Coast of Expressway (ECE) in Peninsula Malaysia. ECE was selected to do this study as the link consists of numerous variations in terrain along the 8860

Every point represents kilometer and polygon of different color where it represents as slope at the study area. Each color has their own slope rate in degree.

4 Figure 6: Slope area (Second Critical Area) Figure 4: Calculated Crosswind Speed Value base on Slope Topographic Factor. For analysis with the GIS software, the length of the road was divided for each kilometer from KM76 (Karak) until KM245 (Kuantan). Every point represents kilometer and polygon of different color where it represents as slope at the study area. Each color has their own slope rate in degree. From the Prone Area analysis, it shows that there are polygons that contribute to the highest slope. The highest slope is viewed at KM133 ( ) as shown in Figure 5.0 and the second highest slope is viewed at KM202 ( ) as depicted in Figure 6.0. Result shows that highest slope induce wind speed rate to become high to that area. The presence of wind to blow with significant speed will make the situation more disorienting to drivers especially along the variation of terrain on the highway. Increase in wind speed indirectly has negative impact in causing road accident. Wind induced accidents during slope topographic conditions are prone to magnify wind effects which lead to hazardous conditions on the road. To establish terrain database along coastal expressway enables a complete description of model using GIS technique. The analysis model gained more clarity on circumstances of accident subjected to cross wind pattern along the terrain change. CONCLUSION With reference to the impact of wind speed on East Coast Expressway (ECE), the conclusion is that variation in topographic may result in a significant increase in the wind speed in the case of no rainfall. For the observed ECE highway, the estimated increase was about 2.86 percent (at the 95 percent confidence interval, 0.5 to 4.4 percent). The wind speed increase is due to increase in slope. Record of slope area along the ECE highway has been visualized using GIS technique. GIS has allowed analysis of overlaid topographic data layers to be linked with ancillary accident data sets to a spatial perspective. This finding is somehow dependent on data statistic of accident. Results have indicated most of accidents for the past record of 5 years were happened due to the influence of wind factor along the topographic area particularly at the benchmark segment of KM187.3 to KM Meanwhile at the benchmark of KM126.0 to KM139.6, the segment of highway has lack of accident because the segment was technically already been alerted with a crosswind road sign. The result of the wind speeds and slopes indicate that awareness of improvement is required at the critical area especially at the accident prone area. It is therefore recommended that responsible authorities should consider constructing wind breaker along the accident prone areas so that road users will be better warned off from the potential danger of wind speed. REFERENCES Figure 5: Highest slope area (Critical Area) [1] Norain, (2012). Effect of wind induced on road accident along ECE Malaysia. UniversitiMalaysia Pahang. [2] Jhon, D. Holmes, (2001). Wind Loading of Structure. [3] S.K. Najid, Azami Zaharin, Ahmad Mahir Razali, Mohd Said Zainol, Kamarulzaman Ibrahim and Kamaruzaman Sopian, (2009). 'Analysing the East Coast Malaysia Wind Speed Data'. [4] World Meteorological Organization, 1983: Guide to Climatological Practices. Second edition (WMONo. 100), Geneva. [5] Ma Nyuk Chaw, (2006). Maintenance of road in district of Kota Marudu, Sabah. 8861

5 [6] Husdal, J., (2000). 'Network Analysis-Raster v/s Vector, a comparison study, University of Leicester, UK'. [7] Klaus Hedegaard and Saren E Larsen, (1983). Wind Speed and Direction Changes due to Terrain Effects revealed by Climatological Data from two sites in Jutland. [8] Young-Kyu Lee, Sungsu Lee and Hak-Sn Kim, (2009). Evaluation of Wind Hazard over Jeju Island. [9] Seungkirl Baek, Hojung Kim, S.Akhtar Ali Shah, Byungha Ahn, 'Architecture of decision support system for incident management-a case study of Republic of Korea', Proc.of the 11th World Congress on ITS (2004). [10] Eckhardt, N., Flahaut, B. and Thomas, I. Spatiotemporalite des accidents de la route en peripheric urbaine. L'exemple de Bruxelles. "RECHERCHE TRANSPORTS SECURITE" 82: pp (2004). [11] Thordarson, S. and Norem, H., (2000). Simulation of two-dimensional wind flow and snow drifting application for roads: Part I & II. in: E. Hjorth-Hansen, I. Holand, S. Løset and H. Norem (eds.), Snow Engineering. Recent Advances and Developments. Proceedings of the fourth International Conference on Snow Engineering, Trondheim, Norway, 2000, pp , A.A. Balkema, Rotterdam. 8862

EVALUATION OF WIND HAZARD OVER JEJU ISLAND

The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 2009, Taipei, Taiwan EVALUATION OF WIND HAZARD OVER JEJU ISLAND Young-Kyu Lee 1, Sungsu Lee 2 and Hak-Sun Kim 3 1 Ph.D Candidate,