Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment

Ayşe Ünal; İslam Gökalp; Serdar Ekinci; Muhammet İsmail Güngör; Davut Izci

doi:10.54287/gujsa.1968177

Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment

Abstract

Road traffic accidents remain a major public health concern, requiring systematic analyses of temporal trends to support evidence-based road safety planning. This retrospective longitudinal study analyzes traffic accident-related injuries and fatalities in Diyarbakir Province, Türkiye, based on official records from 2014 to 2023. The study evaluates temporal trends in accident severity and their associations with selected accident-related variables across monthly, seasonal, and annual scales. Four complementary non-parametric trend analysis methods, including Innovative Trend Analysis (ITA), Innovative Polygon Trend Analysis (IPTA), the Sen Slope Test Method (SSTM), and the Mann-Kendall (MK) trend test, were applied to injury and fatality data. Correlation analysis was also performed to examine the associations between 26 accident-related parameters and injury and fatality counts. The results revealed a statistically significant decreasing trend in injury counts, whereas fatalities showed increasing tendencies during specific periods, indicating that reductions in accident frequency were not accompanied by proportional decreases in accident severity. Seasonal analysis showed that injuries occurred more frequently in summer, while fatalities were relatively higher in winter and spring. Correlation analysis identified significant associations between accident outcomes and several traffic-related variables, highlighting the complex temporal characteristics of road traffic accidents. Overall, the findings demonstrate the importance of integrating complementary non-parametric trend analysis methods for evaluating accident severity patterns and supporting regional road safety assessment.

Keywords

References

Adeyemi, O. J., Arif, A. A., & Paul, R. (2021). Exploring the relationship of rush hour period and fatal and non-fatal crash injuries in the US: A systematic review and meta-analysis. Accident Analysis & Prevention, 163, 106462. https://doi.org/10.1016/j.aap.2021.106462
Altman, N., & Krzywinski, M. (2024). Understanding p-values and significance. Laboratory Animals, 58(5), 443–447. https://doi.org/10.1177/00236772241247106
Basagaña, X., & de la Peña-Ramirez, C. (2023). Ambient temperature and risk of motor vehicle crashes: A countrywide analysis in Spain. Environmental Research, 216, 114599. https://doi.org/10.1016/j.envres.2022.114599
Can, H. N., Aşırdizer, M., Bilvanisi, S., Dursun, R., Duran, L., Karabağ, G., Arıca, E., Bilge, A., Aydın, F., & Sever Tilki, G. D. (2022). The evaluation of blood alcohol concentration of drivers involved in traffic accidents or suspected for alcohol in the roadside controls in four big cities of Türkiye. The Bulletin of Legal Medicine [Adli Tıp Bülteni], 27(2), 129–135. https://doi.org/10.17986/blm.1572
Çelik, Ş. (2013). Time Series Analysis and Its Applications to Data on Traffic Accidents [Zaman Serileri Analizi ve Trafik Kazası Verilerine Uygulanması]. Iğdır University Journal of the Institute of Science and Technology [Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi], 3(4), 43–51. https://izlik.org/JA96HA95ZB
DeGroat, B. (2009). Fall Driving More Hazardous Than Summer or Winter. The UMTRI Research Review, 40(3), 6-6.
DG. (2025). Diyarbakır Governorship [Diyarbakır Valiliği]. http://www.diyarbakir.gov.tr/ (Accessed:01.04.2025).
DMM. (2025). Diyarbakır Metropolitan Municipality [Diyarbakır Büyükşehir Belediyesi]. https://www.diyarbakir.bel.tr/ (Accessed:01.04.2025).

Dogrul, G., & Alkan, M. (2022). Investigation of fatal traffic accidents occurring outside of the city in Turkey using data mining. Selcuk University Journal of Engineering Sciences, 21(2), 75–85.
Doucette, M. L., Tucker, A., Auguste, M. E., Watkins, A., Green, C., Pereira, F. E., Borrup, K. T., Shapiro, D., & Lapidus, G. (2021). Initial impact of COVID-19’s stay-at-home order on motor vehicle traffic and crash patterns in Connecticut: An interrupted time series analysis. Injury Prevention, 27(1), 3–9. https://doi.org/10.1136/injuryprev-2020-043945
Erenler, A. K., & Gümüş, B. (2019). Analysis of road traffic accidents in Turkey between 2013 and 2017. Medicina, 55(10), 679. https://doi.org/10.3390/medicina55100679
Ersen, M., Büyüklü, A. H., & Taşabat Erpolat, S. (2021). Analysis of fatal and injury traffic accidents in Istanbul Sarıyer district with spatial statistics methods. Sustainability, 13(19), 11039. https://doi.org/10.3390/su131911039
Fidan, S., Yılmaz, M., Ateş, E., & Altundal Öncü, M. (2024). Mekânsal ve zamansal perspektiften Ankara'daki trafik kazaları: Ölümlü ve yaralanmalı olayların analizi. Journal of Geography, (48), 193–211. https://doi.org/10.26650/JGEOG2024-1438461
Hamed, K. H., & Ramachandra Rao, A. (1998). A modified Mann-Kendall trend test for autocorrelated data. Journal of Hydrology, 204(1–4), 182–196. https://doi.org/10.1016/S0022-1694(97)00125-X
Helsel, D. R., & Hirsch, R. M. (2002). Statistical methods in water resources (Vol. 323). U.S. Geological Survey.
Hirsch, R. M., Slack, J. R., & Smith, R. A. (1982). Techniques of trend analysis for monthly water quality data. Water Resources Research, 18(1), 107–121. https://doi.org/10.1029/WR018i001p00107
Hossain, A., Rahman, M. A., & Sun, X. (2022). Roadway crash trend analysis with innovative trend analysis and Mann-Kendall test. In: Southeast Symposium on Contemporary Engineering Topics (SSCET). September, 2022, Little Rock, Arkansas. https://doi.org/10.6084/m9.figshare.21257058.v1
Hyodo, S., & Hasegawa, K. (2021). Factors affecting analysis of the severity of accidents in cold and snowy areas using the ordered probit model. Asian Transport Studies, 7, 100035. https://doi.org/10.1016/j.eastsj.2021.100035
Kendall, M. G. (1975). Rank Correlation Methods (4th Ed.). Charles Griffin, London.
Kričković, E., Lukić, T., Srejić, T., Stojšić-Milosavljević, A., Stojanović, V., & Kričković, Z. (2024). Spatial-temporal and trend analysis of traffic accidents in AP Vojvodina (North Serbia). Open Geosciences, 16(1), 20220630. https://doi.org/10.1515/geo-2022-0630
Kulaç, S., & Arslankaya, S. (2024). Traffic Accident Risk Assessment with Fuzzy Logic Approach [Bulanık Mantık Yaklaşımı ile Trafik Kazası Riskinin Değerlendirilmesi]. Journal of Traffic and Transportation Research [Trafik ve Ulaşım Araştırmaları Dergisi], 7(1), 44–56. https://doi.org/10.38002/tuad.1400522
Kuşkapan, E., Alemdar, K. D., Kaya, Ö., & Çodur, M. Y. (2019). Traffic accidents caused by pedestrians in Turkey. International Journal for Traffic and Transport Engineering, 9(1), 118–126. https://doi.org/10.7708/ijtte.2019.9(1).09
Macioszek, E., & Kurek, A. (2021). Road traffic distribution on public holidays and workdays on selected road transport network elements. Transport Problems, 16(1), 127–138. https://doi.org/10.21307/tp-2021-011
Manikandan, M., Prasad, V., Mishra, A. K., Konduru, R. K., & Newtonraj, A. (2018). Forecasting road traffic accident deaths in India using seasonal autoregressive integrated moving average model. International Journal of Community Medicine and Public Health, 5(9), 3962-3968. https://doi.org/10.18203/2394-6040.ijcmph20183579
Mann, H. B. (1945). Nonparametric tests against trend. Econometrica, 13(3), 245–259. https://doi.org/10.2307/1907187
Mazrekaj, R., Đurin, B., Shala, A., Lajqi, S., & Alamatian, E. (2022). A novel approach to analysis of road accidents using the trend analysis and IPTA method: A case study of Kosovo. The Baltic Journal of Road and Bridge Engineering, 17(4), 1–17. https://doi.org/10.7250/bjrbe.2022-17.576
Melchor, I., Nolasco, A., Moncho, J., Quesada, J. A., Pereyra-Zamora, P., García-Senchermés, C., Tamayo-Fonseca, N., Martínez-Andreu, P., Valero, S., & Salinas, M. (2015). Trends in mortality due to motor vehicle traffic accident injuries between 1987 and 2011 in a Spanish region (Comunitat Valenciana). Accident Analysis & Prevention, 77, 21–28. https://doi.org/10.1016/j.aap.2015.01.023
Muguro, J. K., Sasaki, M., Matsushita, K., & Njeri, W. (2020). Trend analysis and fatality causes in Kenyan roads: A review of road traffic accident data between 2015 and 2020. Cogent Engineering, 7(1), 1797981. https://doi.org/10.1080/23311916.2020.1797981
Ngwira, G. M., Bolaane, B., & Parida, B. P. (2023). Investigating the trend of road traffic fatalities in Malawi using Mann-Kendall statistic. Heliyon, 9(2), e13700. https://doi.org/10.1016/j.heliyon.2023.e13700
Özçelebi, M. A. (2024). GIS Based Temporal and Spatial Analysis of Road Traffic Accidents in Samsun [Samsun’da Kara Yolu Trafik Kazalarının CBS Tabanlı Zamansal ve Mekânsal Analizi]. Mavi Atlas, 12(2), 433–458. https://doi.org/10.18795/gumusmaviatlas.1480455
Pastagia, J., & Mehta, D. (2022). Application of innovative trend analysis on rainfall time series over Rajsamand district of Rajasthan state. Water Supply, 22(9), 7189–7196. https://doi.org/10.2166/ws.2022.276
Sangkharat, K., Thornes, J. E., Wachiradilok, P., & Pope, F. D. (2021). Determination of the impact of rainfall on road accidents in Thailand. Heliyon, 7(2), e06061. https://doi.org/10.1016/j.heliyon.2021.e06061
Sen, P. K. (1968). Estimates of the regression coefficient based on Kendall’s tau. Journal of the American Statistical Association, 63(324), 1379–1389. https://doi.org/10.1080/01621459.1968.10480934
Shahid, S., Minhans, A., Che Puan, O., Hasan, S. A., & Ismail, T. (2015). Spatial and temporal pattern of road accidents and casualties in Peninsular Malaysia. Jurnal Teknologi (Sciences & Engineering), 76(14). https://doi.org/10.11113/jt.v76.5843
Sümer, N., & Kaygısız, Ö. (2015). The interplay between enforcement, tickets issued, and traffic safety in Turkey: Analyses of 2008-2012 [Türkiye’de denetleme, cezalar ve trafik güvenliği göstergeleri arasındaki ilişkiler: 2008–2012 yılları analizi]. Turkish Journal of Public Health [Türkiye Halk Sağlığı Dergisi], 13(3), 193–205. https://doi.org/10.20518/thsd.11797
Şen, Z. (2012). Innovative trend analysis methodology. Journal of Hydrologic Engineering, 17(9), 1042–1046. https://doi.org/10.1061/(ASCE)HE.1943-5584.0000556
Şen, Z., Şişman, E., & Dabanli, I. (2019). Innovative Polygon Trend Analysis (IPTA) and applications. Journal of Hydrology, 575, 202–210. https://doi.org/10.1016/j.jhydrol.2019.05.028
Theil, H. (1950). A Rank-Invariant Method of Linear and Polynomial Regression Analysis. Indagationes Mathematicae, 12, 173.
TURKSTAT/TÜİK (The Turkish Statistical Institute). (2026a). Road Traffic Accident Statistics, 2025 (Corrected). https://veriportali.tuik.gov.tr/en/press/58133. (Accessed:28.09.2026).
TURKSTAT/TÜİK (The Turkish Statistical Institute). (2026b). Number of traffic accidents involving death or injury, persons killed and injured by province, 2025. https://veriportali.tuik.gov.tr/en/press/58133. (Accessed:28.09.2026).
TURKSTAT/TÜİK (The Turkish Statistical Institute). (2026c). The Results of Address Based Population Registration System, 2025. https://veriportali.tuik.gov.tr/tr/press/53899. (Accessed:28.09.2026).
Weast, R. (2018). Temporal factors in motor-vehicle crash deaths: Ten years later. Journal of Safety Research, 65, 125–131. https://doi.org/10.1016/j.jsr.2018.02.011
WHO. World Health Organization. (2023). Global status report on road safety 2023. https://www.who.int/publications/i/item/9789240086517
Yasmin, S., & Eluru, N. (2018). A joint econometric framework for modeling crash counts by severity. Transportmetrica A: Transport Science, 14(3), 230–255. https://doi.org/10.1080/23249935.2017.1369469
Yıldırım, V., Yurdakul, E., Adana Karaağaç, G., Koçer, M., & Uyguçgil, H. (2023). Spatiotemporal Analysis of Traffic Accidents in Eskişehir City Center [Eskişehir Kent Merkezindeki Trafik Kazalarının Zamana Bağlı Konumsal Analizi]. Turkish Journal of Remote Sensing and GIS [Türk Uzaktan Algılama ve CBS Dergisi], 4(1), 17–32. https://doi.org/10.48123/rsgis.1167844
Yousefzadeh-Chabok, S., Ranjbar-Taklimie, F., Malekpouri, R., & Razzaghi, A. (2016). A time series model for assessing the trend and forecasting the road traffic accident mortality. Archives of Trauma Research, 5(3), e36570. https://doi.org/10.5812/atr.36570
Yue, S., Pilon, P., & Cavadias, G. (2002). Power of the Mann-Kendall and Spearman’s rho tests for detecting monotonic trends in hydrological series. Journal of Hydrology, 259(1–4), 254–271. https://doi.org/10.1016/S0022-1694(01)00594-7
Zhang, P., Wang, C., Easa, S. M., Chen, F., & Cheng, J. (2024). Temporal analysis of factors affecting injury severities of expressway rear-end crashes during weekdays and weekends. Transportation Planning and Technology, 47(7), 1111–1132. https://doi.org/10.1080/03081060.2024.2335514
Zou, Y., Zhang, Y., & Cheng, K. (2021). Exploring the impact of climate and extreme weather on fatal traffic accidents. Sustainability, 13(1), 390. https://doi.org/10.3390/su13010390

Details

Primary Language

English

Subjects

Transportation Engineering

Journal Section

Research Article

Authors

Ayşe Ünal ^*
0000-0002-3262-135X
Türkiye

İslam Gökalp
0000-0003-3198-3508
Türkiye

Serdar Ekinci
0000-0002-7673-2553
Türkiye

Muhammet İsmail Güngör
0009-0003-9241-770X
Türkiye

Davut Izci
0000-0001-8359-0875
Türkiye

Early Pub Date

September 29, 2026

Publication Date

September 30, 2026

Submission Date

June 10, 2026

Acceptance Date

September 2, 2026

Published in Issue

Year 2026 Volume: 13 Number: 3

DOI

https://doi.org/10.54287/gujsa.1968177

IZ

https://izlik.org/JA34DM68BC

Cite

RIS / Bibtex

APA

Ünal, A., Gökalp, İ., Ekinci, S., Güngör, M. İ., & Izci, D. (2026). Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment. Gazi University Journal of Science Part A: Engineering and Innovation, 13(3), 1327-1353. https://doi.org/10.54287/gujsa.1968177

AMA

1.Ünal A, Gökalp İ, Ekinci S, Güngör Mİ, Izci D. Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment. GU J Sci, Part A. 2026;13(3):1327-1353. doi:10.54287/gujsa.1968177

Chicago

Ünal, Ayşe, İslam Gökalp, Serdar Ekinci, Muhammet İsmail Güngör, and Davut Izci. 2026. “Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment”. Gazi University Journal of Science Part A: Engineering and Innovation 13 (3): 1327-53. https://doi.org/10.54287/gujsa.1968177.

EndNote

Ünal A, Gökalp İ, Ekinci S, Güngör Mİ, Izci D (September 1, 2026) Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment. Gazi University Journal of Science Part A: Engineering and Innovation 13 3 1327–1353.

IEEE

[1]A. Ünal, İ. Gökalp, S. Ekinci, M. İ. Güngör, and D. Izci, “Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment”, GU J Sci, Part A, vol. 13, no. 3, pp. 1327–1353, Sept. 2026, doi: 10.54287/gujsa.1968177.

ISNAD

Ünal, Ayşe - Gökalp, İslam - Ekinci, Serdar - Güngör, Muhammet İsmail - Izci, Davut. “Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment”. Gazi University Journal of Science Part A: Engineering and Innovation 13/3 (September 1, 2026): 1327-1353. https://doi.org/10.54287/gujsa.1968177.

JAMA

1.Ünal A, Gökalp İ, Ekinci S, Güngör Mİ, Izci D. Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment. GU J Sci, Part A. 2026;13:1327–1353.

MLA

Ünal, Ayşe, et al. “Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment”. Gazi University Journal of Science Part A: Engineering and Innovation, vol. 13, no. 3, Sept. 2026, pp. 1327-53, doi:10.54287/gujsa.1968177.

Vancouver

1.Ayşe Ünal, İslam Gökalp, Serdar Ekinci, Muhammet İsmail Güngör, Davut Izci. Trend Analysis of Road Traffic Accident Injuries and Fatalities Using Nonparametric Statistical Methods: A Temporal and Seasonal Assessment. GU J Sci, Part A. 2026 Sep. 1;13(3):1327-53. doi:10.54287/gujsa.1968177