A Comprehensive Review on Risk Factors Affecting the Crash Severity

Milad Safari, Seyed Shamseddin Alizadeh, Homayoun Sadeghi Bazargani, Atefeh Aliashrafi, Azam Maleki, Parosa Moshashaei, Mohammad Shakerkhatibi


As a matter of growing machinery life, traffic crashes are considered an inevitable source of injuries and costs around the world. Regarding to increasing traffic accident outcomes, controlling the current status is necessary. In this way, identifying risk factors affecting the crash severity is an essential step toward initiating a convincing solution. The core objective of this study was to categorize the risk factors affecting the severity of crashes. Data needed for this study were gathered through searching Web of Science, Google Scholar, and Science Direct databases using the keywords included fatal and crash, injuries and crash, fatal and traffic accident, and injuries and traffic accident. Based on 83 selected studies for review, factors affecting the crash severity divided into five factors and forty-seven sub-factors. The most prevalent sub-factors were age, sex, safety belts, alcohol and drug use, speed, weather conditions, lighting conditions, time of the day and week, vehicle kind, road condition, collision type and crash location. Many risk factors affect crash severity and determination of the most important ones can be a prelude in reducing the effects. Therefore, the conclusion of this review can assist to traffic safety experts, police and contribute to distinguishing and monitoring the risk factors affecting crash severity transportation agencies.


Traffic; Crash severity; Risk-factors; Road transport System

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ChikkaKrishna NK, Parida M, Jain S. Identifying safety factors associated with crash frequency and severity on nonurban four-lane highway stretch in India. Journal of Transportation Safety & Security. 2017;9(sup1):6-32.

Evans L. The dominant role of driver behavior in traffic safety. Am J Public Health. 1996;86(6):784-6.

Chen C, Zhang G, Qian Z, Tarefder RA, Tian Z. Investigating driver injury severity patterns in rollover crashes using support vector machine models. Accid Anal Prev. 2016;90:128-39.

La QN, Van Duong D, Lee AH, Meuleners LB. Factors underlying bus-related crashes in Hanoi, Vietnam. Transp Res Part F Traffic Psychol Behav. 2017;46:426-37.

Conroy C, Hoyt DB, Eastman AB, Erwin S, Pacyna S, Holbrook TL, et al. Rollover crashes: predicting serious injury based on occupant, vehicle, and crash characteristics. Accid Anal Prev. 2006;38(5):835-42.

Djalalinia S, Saeedi Moghaddam S, Moradi-Lakeh M, Shahraz S, Naghavi M, Murray CJ, et al. Prevalence and years lived with disability of 310 diseases and injuries in Iran and its neighboring countries, 1990-2015: findings from Global Burden of Disease Study 2015. Arch Iran Med. 2017;20(7):392-02.

Norton R, Kobusingye O. Injuries. N Engl J Med. 2013;368(18):1723-30.

Másilková M. Health and social consequences of road traffic accidents. Kontakt. 2017;19(1):e43-e7.

Pokorný V, KOL A. Traumatologie. Praha: Triton, 2002.

Ayuso M, Bermúdez L, Santolino M. Copula-based regression modeling of bivariate severity of temporary disability and permanent motor injuries. Accid Anal Prev. 2016;89:142-50.

Guria JC. Length of hospitalization-an indicator of social costs of disabilities from traffic injuries. Accid Anal Prev. 1990;22(4):379-89.

World Health Organization. Global status report on road safety. WHO Web Site; 2015; Available from:: http://www.who.int/violence_injury_prevention/road_safety_status/2015/en/.

Peden M, Scurfield R, Sleet D, Mohan D, Hyder AA, Jarawan E, et al. World report on road traffic injury prevention. World Health Organization Geneva; 2004.

National Highway Traffic Safety Administration. Comparison analysis of fatality trend by age group-1996 to 2005. Washington: NHTSA's National Center for Statistics and Analysis; 2007.

Jost G, Allsop R, Steriu M. Back on Track to Reach the EU 2020 Road Safety Target? 7th Road Safety PIN Report 2013.

Goniewicz M, Nogalski A, Khayesi M, Lübek T, Zuchora B, Goniewicz K, et al. Pattern of road traffic injuries in Lublin County, Poland. Cent Eur J Public Health. 2012;20(2):116.

World Health Organization. Road traffic injuries. WHO Web Site; 2018; Available from: https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries.

Murray CJ, Lopez AD, WHO. The global burden of disease: a comprehensive assessment of mortality and disability from diseases, injuries, and risk factors in 1990 and projected to 2020: summary1996.

O'neill B, Mohan D. Reducing motor vehicle crash deaths and injuries in newly motorising countries. BMJ: British Medical Journal. 2002;324(7346):1142.

Ameratunga S, Hijar M, Norton R. Road-traffic injuries: confronting disparities to address a global-health problem. Lancet. 2006;367(9521):1533-40.

García-Altés A, Pérez K. The economic cost of road traffic crashes in an urban setting. Inj Prev. 2007;13(1):65-68.

Ziyab AH, Akhtar S. Incidence and trend of road traffic injuries and related deaths in Kuwait: 2000-2009. Injury. 2012;43(12):2018-22.

World Health Organization. World Health Day: Road safety is no accident. WHO Web Site; 2004; Available from:


Hyder AA, Amach OH, Garg N, Labinjo MT. Estimating the burden of road traffic injuries among children and adolescents in urban South Asia. Health policy. 2006;77(2):129-39.

Anderson TK. Using geodemographics to measure and explain social and environment differences in road traffic accident risk. Environment and Planning A. 2010;42(9):2186-00.

Boufous S, Williamson A. Factors affecting the severity of work related traffic crashes in drivers receiving a worker's compensation claim. Accid Anal Prev. 2009;41(3):467-73.

Kaplan S, Prato CG. Risk factors associated with bus accident severity in the United States: A generalized ordered logit model. J Safety Res. 2012;43(3):171-80.

Lee J, Abdel-Aty M, Choi K. Analysis of residence characteristics of at-fault drivers in traffic crashes. Saf Sci. 2014;68:6-13.

Traynor TL. The relationship between regional economic conditions and the severity of traffic crashes. Traffic Inj Prev. 2009;10(4):368-74.

Zhang G, Yau KK, Chen G. Risk factors associated with traffic violations and accident severity in China. Accid Anal Prev. 2013;59:18-25.

Celik AK, Oktay E. A multinomial logit analysis of risk factors influencing road traffic injury severities in the Erzurum and Kars Provinces of Turkey. Accid Anal Prev. 2014;72:66-77.

Theofilatos A, Graham D, Yannis G. Factors affecting accident severity inside and outside urban areas in Greece. Traffic Inj Prev. 2012;13(5):458-67.

Abu-Zidan FM, Eid HO. Factors affecting injury severity of vehicle occupants following road traffic collisions. Injury. 2015;46(1):136-41.

Rifaat SM, Chin HC. Accident severity analysis using ordered probit model. J Adv Transport. 2007;41(1):91-114.

Valent F, Schiava F, Savonitto C, Gallo T, Brusaferro S, Barbone F. Risk factors for fatal road traffic accidents in Udine, Italy. Accid Anal Prev. 2002;34(1):71-84.

Lu JJ, Xing Y, Wang C, Cai X. Risk factors affecting the severity of traffic accidents at Shanghai river-crossing tunnel. Traffic Inj Prev. 2016;17(2):176-80.

Huang H, Chin HC, Haque MM. Severity of driver injury and vehicle damage in traffic crashes at intersections: a Bayesian hierarchical analysis. Accid Anal Prev. 2008;40(1):45-54.

Rifaat S, Chin H, editors. Analysis of severity of single-vehicle crashes in Singapore. TRB 2005 Annual Meeting CD-ROM, Transportation Research Board, National Research Council, Washington DC; 2005.

Bedard M, Guyatt GH, Stones MJ, Hirdes JP. The independent contribution of driver, crash, and vehicle characteristics to driver fatalities. Accid Anal Prev. 2002;34(6):717-27.

Kadilar GO. Effect of driver, roadway, collision, and vehicle characteristics on crash severity: a conditional logistic regression approach. Int J Inj Contr Saf Promot. 2016;23(2):135-44.

Ma Z, Zhao W, Steven I, Chien J, Dong C. Exploring factors contributing to crash injury severity on rural two-lane highways. J Safety Res. 2015;55:171-76.

Rahim K, Sadeghi KM. Research note: Development of a model considering effective factors on the severity of freeway accidents (case study of the Tehran-Karaj freeway). Journal of transportation research. 2011;8:199-99.

Uddin M, Huynh N. Factors influencing injury severity of crashes involving HAZMAT trucks. IJTST. 2017.

Abdel-Aty M. Analysis of driver injury severity levels at multiple locations using ordered probit models. J Safety Res. 2003;34(5):597-03.

Islam M, Hernandez S. Large truck-involved crashes: exploratory injury severity analysis. IJTE. 2013;139(6):596-04.

Kim K, Brunner IM, Yamashita E. Modeling fault among accident-Involved pedestrians and motorists in Hawaii. Accid Anal Prev. 2008;40(6):2043-49.

Kockelman KM, Kweon Y-J. Driver injury severity: an application of ordered probit models. Accid Anal Prev. 2002;34(3):313-21.

Yau KK. Risk factors affecting the severity of single vehicle traffic accidents in Hong Kong. Accid Anal Prev. 2004;36(3):333-40.

Yau KK, Lo H-P, Fung SH. Multiple-vehicle traffic accidents in Hong Kong. Accid Anal Prev. 2006;38(6):1157-61.

Zhang J, Lindsay J, Clarke K, Robbins G, Mao Y. Factors affecting the severity of motor vehicle traffic crashes involving elderly drivers in Ontario. Accid Anal Prev. 2000;32(1):117-25.

Anarkooli AJ, Hosseinpour M, Kardar A. Investigation of factors affecting the injury severity of single-vehicle rollover crashes: a random-effects generalized ordered probit model. Accid Anal Prev. 2017;106:399-10.

Mohamed SA, Mohamed K, Al-Harthi HA. Investigating factors affecting the occurrence and severity of rear-end crashes. Transp Res Proc. 2017;25:2098-07.

Michalaki P, Quddus MA, Pitfield D, Huetson A. Exploring the factors affecting motorway accident severity in England using the generalised ordered logistic regression model. J Safety Res. 2015;55:89-97.

Mock CN, Grossman DC, Kaufman RP, Mack CD, Rivara FP. The relationship between body weight and risk of death and serious injury in motor vehicle crashes. Accid Anal Prev. 2002;34(2):221-28.

Anastasopoulos PC, Mannering FL. An empirical assessment of fixed and random parameter logit models using crash-and non-crash-specific injury data. Accid Anal Prev. 2011;43(3):1140-47.

Boufous S, Finch C, Hayen A, Williamson A. The impact of environmental, vehicle and driver characteristics on injury severity in older drivers hospitalized as a result of a traffic crash. J Safety Res. 2008;39(1):65-72.

Castro M, Paleti R, Bhat CR. A spatial generalized ordered response model to examine highway crash injury severity. Accid Anal Prev. 2013;52:188-03.

Crandall CS, Olson LM, Sklar DP. Mortality reduction with air bag and seat belt use in head-on passenger car collisions. Am J Epidemiol. 2001;153(3):219-24.

Evans L. Safety-belt effectiveness: the influence of crash severity and selective recruitment. Accid Anal Prev. 1996;28(4):423-33.

Petridou E, Skalkidou A, Ioannou N, Trichopoulos D. Fatalities from non-use of seat belts and helmets in Greece: a nationwide appraisal. Accid Anal Prev. 1998;30(1):87-91.

Prato CG, Rasmussen TK, Kaplan S. Risk factors associated with crash severity on low-volume rural roads in Denmark. Journal of Transportation Safety & Security. 2014;6(1):1-20.

Wang X, Abdel-Aty M. Analysis of left-turn crash injury severity by conflicting pattern using partial proportional odds models. Accid Anal Prev. 2008;40(5):1674-82.

Abegaz T, Berhane Y, Worku A, Assrat A, Assefa A. Effects of excessive speeding and falling asleep while driving on crash injury severity in Ethiopia: a generalized ordered logit model analysis. Accid Anal Prev. 2014;71:15-21.

Asbridge M, Hayden JA, Cartwright JL. Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analysis. Bmj. 2012;344:e536.

Behnood A, Mannering FL. The effects of drug and alcohol consumption on driver injury severities in single-vehicle crashes. Traffic Inj Prev. 2017;18(5):456-62.

de Carvalho Ponce J, Muñoz DR, Andreuccetti G, de Carvalho DG, Leyton V. Alcohol-related traffic accidents with fatal outcomes in the city of Sao Paulo. Accid Anal Prev. 2011;43(3):782-87.

Hels T, Lyckegaard A, Simonsen KW, Steentoft A, Bernhoft IM. Risk of severe driver injury by driving with psychoactive substances. Accid Anal Prev. 2013;59:346-56.

Khattak AJ, Schneider RJ, Targa F. Risk factors in large truck rollovers and injury severity: analysis of single-vehicle collisions. Transportation Research Record. 2003;40.

Kuruc R, Sidlo J, Valent D, Mlynar J, Murarikova B. The responsibility of alcohol-impaired road users in fatal road traffic accidents. Bratislavskẻ Lekárske Listy. 2009;110(12):802-06.

Laude JR, Fillmore MT. Simulated driving performance under alcohol: effects on driver-risk versus driver-skill. Drug Alcohol Depend. 2015;154:271-77.

Öström M, Eriksson A. Single-vehicle crashes and alcohol: a retrospective study of passenger car fatalities in northern Sweden. Accid Anal Prev. 1993;25(2):171-76.

Soderstrom CA, Ballesteros MF, Dischinger PC, Kerns TJ, Flint RD, Smith GS. Alcohol/drug abuse, driving convictions, and risk-taking dispositions among trauma center patients. Accid Anal Prev. 2001;33(6):771-82.

Solnick SJ, Hemenway D. Hit the bottle and run: the role of alcohol in hit-and-run pedestrian fatalities. J Stud Alcohol. 1994;55(6):679-84.

Tsui K, Sze N, So F, Wong S. Association between drink driving and severity of crash injuries to road users. Hong Kong J Emerg Me. 2010;17(1):34-9.

Yan X, Radwan E, Abdel-Aty M. Characteristics of rear-end accidents at signalized intersections using multiple logistic regression model. Accid Anal Prev. 2005;37(6):983-95.

Yang Z, Zhibin L, Pan L, Liteng Z. Exploring contributing factors to crash injury severity at freeway diverge areas using ordered probit model. Procedia Eng. 2011;21:178-85.

Zhu X, Srinivasan S. A comprehensive analysis of factors influencing the injury severity of large-truck crashes. Accid Anal Prev. 2011;43(1):49-57.

Aarts L, Van Schagen I. Driving speed and the risk of road crashes: A review. Accid Anal Prev. 2006;38(2):215-24.

Al-Ghamdi AS. Using logistic regression to estimate the influence of accident factors on accident severity. Accid Anal Prev. 2002;34(6):729-41.

Hassan HM, Al-Faleh H. Exploring the risk factors associated with the size and severity of roadway crashes in Riyadh. J Safety Res. 2013;47:67-74.

Hı́jar M, Carrillo C, Flores M, Anaya R, Lopez V. Risk factors in highway traffic accidents: a case control study. Accid Anal Prev. 2000;32(5):703-9.

Mergia WY, Eustace D, Chimba D, Qumsiyeh M. Exploring factors contributing to injury severity at freeway merging and diverging locations in Ohio. Accid Anal Prev. 2013;55:202-10.

RUNE E. Speed and road accidents An evaluation of the Power Model. The Institute of Transport Economics (TOI) Report. 2004.

Xie Y, Zhao K, Huynh N. Analysis of driver injury severity in rural single-vehicle crashes. Accid Anal Prev. 2012;47:36-44.

Eluru N, Bagheri M, Miranda-Moreno LF, Fu L. A latent class modeling approach for identifying vehicle driver injury severity factors at highway-railway crossings. Accid Anal Prev. 2012;47:119-27.

Jung S, Qin X, Noyce DA. Rainfall effect on single-vehicle crash severities using polychotomous response models. Accid Anal Prev. 2010;42(1):213-24.

Ma Z, Steven I, Chien J, Dong C, Hu D, Xu T. Exploring factors affecting injury severity of crashes in freeway tunnels. Tunn Undergr Sp Tech. 2016;59:100-04.

Mondal P, Sharma N, Kumar A, Vijay P, Bhangale U, Tyagi D. Are Road Accidents Affected by Rainfall? A Case Study from a Large Indian Metropolitan City. Br J Appl Sci Technol. 2011;1(2):16.

Naik B, Tung L-W, Zhao S, Khattak AJ. Weather impacts on single-vehicle truck crash injury severity. J Safety Res. 2016;58:57-65.

Osman M, Paleti R, Mishra S, Golias MM. Analysis of injury severity of large truck crashes in work zones. Accid Anal Prev. 2016;97:261-73.

Osoro M, Ng Z, Oundo J, Omolo J, Luman E. Factors associated with severity of road traffic injuries, Thika, Kenya. PAMJ. 2011;8(1).1-8

Cerwick DM, Gkritza K, Shaheed MS, Hans Z. A comparison of the mixed logit and latent class methods for crash severity analysis. Analytic Methods in Accident Research. 2014;3:11-27.

Duncan C, Khattak A, Council F. Applying the ordered probit model to injury severity in truck-passenger car rear-end collisions. Transport Res Rec. 1998(1635):63-71.

Gray RC, Quddus MA, Evans A. Injury severity analysis of accidents involving young male drivers in Great Britain. J Safety Res. 2008;39(5):483-95.

Islam M, Hernandez S. Modeling injury outcomes of crashes involving heavy vehicles on Texas highways. Transport Res Rec. 2013(2388):28-36.

Siddiqui N, Chu X, Guttenplan M. Crossing locations, light conditions, and pedestrian injury severity. Transport Res Rec. 2006(1982):141-49.

Wang Y, Zhang W. Analysis of roadway and environmental factors affecting traffic crash severities. Transp Res Proc 2017;25:2119-25.

Mussone L, Bassani M, Masci P. Analysis of factors affecting the severity of crashes in urban road intersections. Accid Anal Prev. 2017;103:112-22.

Lee J, Mannering F. Impact of roadside features on the frequency and severity of run-off-roadway accidents: an empirical analysis. Accid Anal Prev. 2002;34(2):149-61.

Quddus MA, Noland RB, Chin HC. An analysis of motorcycle injury and vehicle damage severity using ordered probit models. J Safety Res. 2002;33(4):445-62.

Simončič M. Road accidents in Slovenia involving a pedestrian, cyclist or motorcyclist and a car. Accid Anal Prev. 2001;33(2):147-56.

Adanu EK, Hainen A, Jones S. Latent class analysis of factors that influence weekday and weekend single-vehicle crash severities. Accid Anal Prev. 2018;113:187-92.

Barua U, Tay R. Severity of urban transit bus crashes in Bangladesh. J Adv Transport. 2010;44(1):34-41.

Yuan Q, Lu M, Theofilatos A, Li Y-B. Investigation on occupant injury severity in rear-end crashes involving trucks as the front vehicle in Beijing area, China. Chin J Traumatol. 2017;20(1):20-6.

Vorko-Jović A, Kern J, Biloglav Z. Risk factors in urban road traffic accidents. J Safety Res. 2006;37(1):93-98.

Chen C, Zhang G, Tarefder R, Ma J, Wei H, Guan H. A multinomial logit model-Bayesian network hybrid approach for driver injury severity analyses in rear-end crashes. Accid Anal Prev. 2015;80:76-88.

Farmer CM, Lund AK. Rollover risk of cars and light trucks after accounting for driver and environmental factors. Accid Anal Prev. 2002;34(2):163-73.

Islam S, Hossain AB, Barnett TE. Comprehensive Injury Severity Analysis of SUV and Pickup Truck Rollover Crashes: Alabama Case Study. Transport Res Rec. 2016(2601):1-9.

Khattak A, Rocha M. Are SUVs" supremely unsafe vehicles"?: Analysis of rollovers and injuries with sport utility vehicles. Transport Res Rec. 2003(1840):167-77.

Izquierdo FA, Ramírez BA, Rodríguez EB. The interurban DRAG-Spain model: The main factors of influence on road accidents in Spain. Res Transp Econ. 2013;37(1):57-65.

Haadi A-R. Identification of Factors that Cause Severity of Road Accidents in Ghana: A Case Study of the Northern Region: Kwame Nkrumah University of Science and Technology; 2012.

Chen C, Zhang G, Huang H, Wang J, Tarefder RA. Examining driver injury severity outcomes in rural non-interstate roadway crashes using a hierarchical ordered logit model. Accid Anal Prev. 2016;96:79-87.

Deng Z, Ivan J, Gårder P. Analysis of factors affecting the severity of head-on crashes: two-lane rural highways in connecticut. Transport Res Rec. 2006(1953):137-46.

Dissanayake S, Roy U. Crash severity analysis of single vehicle run-off-road crashes. JTTs. 2014;4(01):1.

Forkenbrock DJ, Hanley PF. Fatal crash involvement by multiple-trailer trucks. Transp Res Part A Policy Pract. 2003;37(5):419-33.

Garrido R, Bastos A, de Almeida A, Elvas JP. Prediction of road accident severity using the ordered probit model. Transp Res Proc. 2014;3:214-23.

Shaheed MSB, Gkritza K, Zhang W, Hans Z. A mixed logit analysis of two-vehicle crash severities involving a motorcycle. Accid Anal Prev. 2013;61:119-28.

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