Tropical Medicine and International Health

doi:10.1111/tmi.12436

volume 20 no 3 pp 293–303 march 2015

Differential patterns, trends and hotspots of road traffic injuries on different road networks in Vellore district, southern India Venkata Raghava Mohan1, Rajiv Sarkar1, Vinod Joseph Abraham1, Vinohar Balraj1 and Elena N Naumova2 1 Christian Medical College, Vellore, India 2 Tufts University School of Engineering

Abstract

objective To describe spatial and temporal profiles of Road Traffic Injuries (RTIs) on different road networks in Vellore district of southern India. methods Using the information in the police maintained First Information Reports (FIRs), daily time series of RTI counts were created and temporal characteristics were analysed with respect to the vehicle, road types and time of the day for the period January 2005 to May 2007. Daily incidence and trend of RTIs were estimated using a Poisson regression analysis. results Of the reported 3262 RTIs, 52% had occurred on the National Highway (NH). The overall RTI rate on the NH was 8.8/100 000 vehicles per day with significantly higher pedestrian involvement. The mean numbers of RTIs were significantly higher on weekends. Thirteen percentage of all RTIs were associated with fatalities. Hotspots are major town junctions, and RTI rates differ over different stretches of the NH. conclusion In India, FIRs form a valuable source of RTI information. Information on different vehicle profile, RTI patterns, and their spatial and temporal trends can be used by administrators to devise effective strategies for RTI prevention by concentrating on the high-risk areas, thereby optimising the use of available personnel and resources. keywords First Information Reports, hotspots, India, Poisson regression analysis, road traffic injuries, Vellore

Introduction Road traffic injuries (RTIs) are a major but neglected public health problem worldwide with an estimated 50 million people getting injured and 1.2 million dying annually (Peden et al. 2004). In the absence of appropriate action, RTIs are expected to be the third major contributor to the global burden of disease and injuries. Projections indicate that South Asia will have the largest increase in road traffic deaths, of 144%, twice the average rate of increase for other World Bank regions in the near future (Murray & Lopez 2012). Low- and middle-income countries (LMIC) account for about 85% of mortality and up to 90% of the annual disability-adjusted life years (DALYs) lost due to RTIs with an estimated economic loss of up to 1.5% of the gross national product (GNP) (Jacobs et al. 2000). Fatalities due to road crashes are steadily declining in the West, while the developing countries are experiencing a rise. The Asia-Pacific region, Middle East

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and Africa (excluding South Africa) have experienced up to 40% increase in deaths due RTIs between 1987 and 1995 (Jacobs et al. 2000). Many Asian countries are currently in a phase where vehicle ownership increases twice as fast as per capita income, which is expected to last for another two decades. It has been estimated that the vehicle stock in China would increase twentyfold by the end of the year 2030. Apart from the important challenges in terms of road infrastructure and fuel delivery faced by the developing nations, increasing RTIs as a result of increase in the vehicles remains a key area of concern (Dargay et al. 2007). India is facing a rapid increase in the motor vehicles with 6 million new motor vehicles sold every year (Gururaj 2008) and is expected to top in the numbers of cars on its roads by 2050 (Gulati & Choudhary 2012). Over the past three decades, India has experienced an increase in the RTI-related fatality, whereas it has decreased significantly in developed and highly 293

Tropical Medicine and International Health

volume 20 no 3 pp 293–303 march 2015

V. R. Mohan et al. Traffic injuries in Vellore, India

motorised countries (Mohan 2004a,b). Recent studies suggest that injuries contribute to 13%–18% of total deaths in India and RTIs are the sixth leading cause of death with higher morbidity, mortality and socio-economic losses among the young- and middle-aged populations (Ministry of Health & Family Welfare 2004; Joshi et al. 2006; Gajalakshmi & Peto 2007). The number of RTI-related fatalities has been increasing by 6– 8% per year since 2004 (NCRB 2008; Government of India, Ministry of Road Transport & Highways 2012). The current fatality rate is over 100 per million persons, 25 times more than that of the developed countries (Mohan 2009). A conservative estimate of the ratio between fatalities, injuries requiring hospital treatment and minor injuries in India is around 1:15:70 (Mohan 2004a,b). In the year 2011, 30% and 24.6% of all reported RTIs in India occurred on the National Highways (NHs) and the State Highways (SHs), respectively (Government of India, Ministry of Road Transport & Highways 2012). Country level information regarding contributing factors to fatality by road-user categories except for selected is not widely available. Studies from New Delhi show that vulnerable road users (pedestrians, bicyclists and two-wheeler riders) accounted for 84% of the total fatalities, whereas car occupants were involved in only 3%. On rural highways, the road users and car occupants accounted for 67% and 15% of the fatalities, respectively (Tiwari et al. 2000; Mohan et al. 2009). There are wide variations within the states in India in terms of the burden of RTIs and associated fatalities with 90% of RTIs occurring in 13 (of 28) states (Government of India, Ministry of Road Transport & Highways 2012). Around 1300 injuries and 370 deaths due to RTIs are reported every day in India, with the state of Tamil Nadu reporting the highest numbers (NCRB 2011). Despite the high burden of RTIs, there is a paucity of information on the real extent of the problem and appropriate information on the distributions, patterns and outcomes (Khambete 2011). This study investigated the profile of RTIs in Vellore district, Tamil Nadu, in southern India. National Highway (NH) 46, which passes through the district, is part of the Golden Quadrilateral road network connecting Delhi, Mumbai, Kolkata and Chennai, spanning 5846 km of four/six lane express highways. While the Golden Quadrilateral contributes to less than 2% of India’s road network, it carries about 40% of the country’s traffic, accounting for one-third of its traffic deaths. The study aims to describe the temporal and spatial profiles of RTIs using the reported information from the district police authorities on the NH 46 and other smaller 294

roads in Vellore for the period January 2005 and May 2007.

Methods Study area In Vellore, the NH, State Highway (SH) and other roads (corporation, municipality, township and village panchayat roads) contribute 227.2 km, 122 km and 5230.5 km of the total road network in the district (Figure 1) (District Administration Vellore 2010). All the RTIs occurring on the NH 46, SHs and other smaller roads in Vellore district between 1 January 2005 and 15 May 2007, (865 days) were analysed. The study was approved by the Institutional Review Board of Christian Medical College, Vellore. Data source The First Information Reports (FIRs) of all the RTIs, which occurred between January 2005 and May 2007 in Vellore district, were collected from the district Police Superintendent’s office which consisted of data from 51 reporting police stations. De-identified data including the time, description of the place of incident, vehicles involved, approximate distance from the reporting police station, total number of people injured and fatalities and the primary causes for the RTIs were extracted and stored in an electronic format at the Department of Community Health, Christian Medical College (CMC), Vellore. To assess the vehicular density and traffic patterns at two toll booths on the NH 46, trained field personnel conducted an independent survey. Information regarding type of vehicle and direction of travel was collected in 6h shifts to obtain an estimate of the total number of vehicles and types over 1 week, which was used to calculate the rates of RTI on the NH. Statistical analysis Exploratory analysis. Data from the FIRs were entered in Microsoft Excel 2002, and statistical analysis was carried out using SPSS v 15.0 software. The primary vehicles involved in the incidents were categorised into ‘heavy motor vehicles’ (HMV, which include buses, trucks, tractors), ‘light motor vehicles’ (LMV, which include cars, jeeps, vans, sports utility vehicles), ‘motor bikes’ and ‘others’ (which include three wheelers, bicycles, carts, etc.). The roads on which the RTIs occurred were categorised into NH, SH and other roads, and

© 2014 John Wiley & Sons Ltd

Tropical Medicine and International Health

volume 20 no 3 pp 293–303 march 2015

V. R. Mohan et al. Traffic injuries in Vellore, India

N

Vellore district

The Golden Quadrilateral State roads

0 12.5 25

50

75

100 km

Figure 1 The Golden Quadrilateral and the National Highway 46 passing through Vellore district.

trends were studied for three different road types in the district. The mortality and fatality associated with the RTIs were compared using a chi-square (v2) test, and the mean numbers of RTIs were compared using a one-way analysis of variance (ANOVA) test. When applicable, odds ratios along with confidence intervals were calculated. Analysis of temporal features. RTI patterns were studied with respect to four different time frames (00:00 to 06:00 hours; 06:00 to 12:00 hours; 12:00 to 18:00 hours; and 18:00 to 24:00 hours) and different road types. Subanalysis for the RTIs occurring on the NH focused on the rates of RTIs with respect to vehicle categories and time of the event. The rates were compared under assumption of constant vehicular density and variability associated with random Poisson-distributed event occurrences. Using the information from the © 2014 John Wiley & Sons Ltd

FIRs, based on the reported date and time of the RTIs, daily time series of counts were created for all RTIs and fatal RTIs. Temporal characteristics were analysed with respect to the type of day (weekday or weekend), hour of the day and the type of vehicles involved in RTIs. To examine the daily incidence and trend of RTIs, Poisson regression analysis was applied to the time series of RTIs in the region with respect to type of day, type of road and associated fatality. The base model for daily time series of each outcome, Yt, can be summarised as follows: ln½EðYt Þ ¼ b0 þ b1 time þ b2 weekday Six individual Poisson regression models were constructed; thus, Yt denotes daily time series of all and fatal RTIs on NH, SHs and other roads; time indicates period of observation in days; weekday is an indicator variable 295

Tropical Medicine and International Health

volume 20 no 3 pp 293–303 march 2015

V. R. Mohan et al. Traffic injuries in Vellore, India

(0 = weekend, 1 = weekday). Based on the results of the models, we estimated the relative risks and their 95% confidence intervals. The predicted numbers of RTIs were estimated for the start of the time series (1 January 2005), at 1 year (1 January 2006) and at the end of time series (13 May 2007). Spatial analysis. Geo-coordinates of all the police stations in the district, major intersections on the NH 46 were collected using Garmin GPS V (Garmin International Inc., Olathe, KS, USA), processed and mapped using ArcView GIS 9.1 software (Environmental Systems Research Institute Inc., Redlands, USA). FIR data on RTI were geo-referenced to the reporting police station and spatially mapped. The NH 46 passing through Vellore district was divided into four major segments based on the location of important towns, junctions and network of State highways joining them, and the RTI rates were spatially linked and mapped for these segments. Using the descriptions on the sites of the events as recorded in the FIRs, all RTIs and fatal RTIs were spatially mapped within 10 km from major intersections on the NH. The trends, spatial and temporal differentials, hotspots for RTIs on the NH were analysed, and segments of the NH with higher risk were identified. Results Three thousand two hundred and sixty two RTIs were reported during the study period, of which 1697 (52%), 975 (29.9%) and 590 (18.1%) had occurred on the NH, SH and other roads, respectively. More than half the RTIs occurring on smaller roads had pedestrian involve-

ment, statistically higher than those on the SH and NH (50.4% vs 39.8% and 33.5%, respectively, P < 0.05). ‘Excess speed’ was documented as the primary cause of RTIs. Other causes including mechanical defects of the vehicle, bad roads, animal involvement, driving under the influence of alcohol and co-passenger faults were documented in

Differential patterns, trends and hotspots of road traffic injuries on different road networks in Vellore district, southern India.

To describe spatial and temporal profiles of Road Traffic Injuries (RTIs) on different road networks in Vellore district of southern India...
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