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2026 Vol.44, Issue 2 Preview Page

Article

Crash Modification Factor Analysis of Intersection Safety Countermeasures: Moderating Effects of Road and Traffic Characteristics

교차로 안전개선대책의 사고보정계수 분석: 도로·교통 특성 조절 효과 중심으로

Jeonghun YANG1
,
Cheol OH2
,
Ilsoo YOON3
,
Tai-jin SONG4*
양 정훈1
,
오 철2
,
윤 일수3
,
송 태진4*
1Deputy General Manager, Traffic Accident Analysis Center, Koroad Road Traffic Authority, Wonju 26466, Korea
2Professor, Department of Transportation and Logistics Engineering, Hanyang University, Ansan 15588, Korea
3Professor, Department of Transportation Systems Engineering, Ajou University, Suwon 16499, Korea
4Associate Professor, Department of Urban Engineering, Chungbuk National University, Cheongju 28644, Korea
1한국도로교통공단 교통사고종합분석센터 차장
2한양대학교 교통ㆍ물류공학과 교수
3아주대학교 교통시스템공학과 교수
4충북대학교 도시공학과 부교수
*Corresponding Author
30 April 2026. pp. 161-183
PDF XML Citation
Abstract

This study empirically examines the effects of various traffic safety countermeasures implemented at intersections on crash frequency and severity, with consideration of road and traffic characteristics. Using data from improvement projects targeting high-risk intersections over the past decade, crash records before and after intervention were collected for 1,892 sites. A total of 104 moderated regression models were constructed, incorporating four key contextual variables: intersection type, major-road speed limit, traffic volume, and road classification. Of these, 95 models yielded statistically significant results, with those including road classification demonstrating particularly strong explanatory power. The analysis revealed that the effectiveness of countermeasures varied by condition: channelization was most effective at three-leg intersections; skid-resistant pavement on high-speed roads; and lighting and jaywalking-prevention facilities at high-volume intersections. Moreover, national highways exhibited greater crash-reduction effects than metropolitan or municipal roads, suggesting a combined influence of road function and speed environment. To support policy development, the study categorized countermeasures into three types—safety facilities, control and regulation facilities, and road/pedestrian space improvements—and proposed installation strategies tailored to specific road conditions. In addition, Korea-specific Crash Modification Factors (CMFs) were derived and compared with international benchmarks, providing a localized empirical basis for evaluating safety interventions. The findings offer practical guidance for prioritizing improvement projects, designing countermeasure combinations, and allocating resources. They also lay the foundation for establishing a Korean Safety Performance Function (SPF), thereby contributing to data-driven traffic safety planning and evaluation.

Keywords
crash modification factor (CMF)
intersection safety
moderated regression analysis
road and traffic characteristics
traffic safety countermeasures

본 연구는 교차로에서 시행되는 다양한 교통안전 개선대책이 도로 및 교통 특성에 따라 교통사고 건수와 사고 심각도에 미치는 영향을 실증적으로 규명하고자 하였다. 이를 위해 최근 10년간 교통사고 잦은 곳 개선사업의 효과분석 자료를 활용하여 총 1,892개 교차로의 개선대책 적용 규모와 전후 사고자료를 수집하였다. 분석에서는 교차로 형태, 주도로 제한속도, 교차로 교통량, 도로 종류의 네 가지 특성을 조절변수로 설정하고, 조절 회귀모형을 통해 개선대책의 차별적 효과를 검증하였다. 연구 결과, 총 104개 모형 중 95개가 통계적으로 유의하였으며, 특히 도로 종류를 포함한 모형의 설명력이 높게 나타났다. 세부적으로는 도류화 시설이 3지 교차로에서, 미끄럼방지포장이 제한속도가 높은 교차로에서, 조명 시설과 무단횡단 금지 시설이 교통량이 많은 교차로에서 높은 사고 감소 효과를 보였다. 또한 일반국도에서는 다수의 개선대책이 특·광역시도 및 시도에 비해 더 높은 효과를 나타냈다. 본 연구는 기존 연구들이 주 효과 분석에 집중했던 한계를 보완하여, 도로 및 교통 특성에 따른 개선대책 효과의 차이를 정량적으로 규명함으로써 한국형 사고보정계수(CMF) 정립과 교차로 안전정책 수립에 실질적 기여를 제공한다.

키워드
사고보정계수(CMF)
교차로 안전
조절 회귀분석
도로 및 교통 특성
교통안전 개선대책
References
1

AASHTO (2010), Highway Safety Manual.

2

Aiken L. S., West S. G. (1991), Multiple Regression: Testing and Interpreting Interactions, CA, Sage Publications.

3

Baek S. Y. (2012), A Study on Preventive Measures for Traffic Accidents Resulting from Jaywalking-Focusing on Crosswalks and Pedestrian Crossing Prevention Facilities, Doctoral dissertation, The University of Seoul.

4

Biswas P., Kang M.-W., Rahman M. (2024), Safety Evaluation of the Combined Effect of Offset Left-Turn Lanes and Flashing-Yellow-Arrow Signals at Signalized Intersections on Multilane Divided Highways in Alabama Using the Empirical Bayes Method, Journal of the Transportation Research Board, 2678(8), 31-45.

10.1177/03611981231213076
5

Chen L., Chen C., Ewing R., McKnight C. E., Srinivasan R., Roe M. (2013), Safety countermeasures and crash reduction in New York City—Experience and lessons learned, Accident Analysis & Prevention, 50, 312-322.

10.1016/j.aap.2012.05.009
6

Choi J. H., Im J. B., Lee S. B. (2016), A Meta Analysis of the Effects of Road Safety Facilities on Accident Reduction: Focusing on Signalized Intersection, J. Korean Soc. Transp., 34(4), Korean Society of Transportation, 291-303.

10.7470/jkst.2016.34.4.291
7

Cohn E. G., Kakar S., Perkins C., Steinbach R., Edwards P. (2020), Red Light Camera Interventions for Reducing Traffic Violations and Traffic Crashes: A Systematic Review, Campbell Systematic Reviews, 16(2), e1091.

10.1002/cl2.109137131412PMC8356316
8

Das S., Sun X., He Y., Wang F., Leboeuf C. (2013), Investigating the Safety Impact of Raised Pavement Markers on Freeways in Louisiana, International Journal of Engineering Research and Innovation, 5(2), 74-80.

9

Elvik R. (2017), Road safety effects of roundabouts: A meta-analysis, Accident Analysis & Prevention, 99, 364-371.

10.1016/j.aap.2016.12.018
10

Galgamuwa U., Dissanayake S. (2019), Evaluation of the Safety Effectiveness of Lane-departure Countermeasures on Two-lane Undivided Roadways using Crash Modification Factors, Journal of Transportation Safety & Security, 11(4), 377-397.

10.1080/19439962.2017.1419523
11

Goldenbeld C., Daniels S., Schermers G. (2019), Red Light Cameras Revisited, Recent Evidence on Red Light Camera Safety Effects, Accident Analysis & Prevention, 128, 139-147.

10.1016/j.aap.2019.04.007
12

Goldstein H. (2015), Multilevel Statistical Models (4th ed.), Wiley.

10.1002/9781118445112.stat05764
13

Gorthy S. C. (2017), Analysis of Right-In, Right-Out Commercial Driveway Safety, Operations and Use of Channelization as Compliance Countermeasure, Master’s Thesis, SC, Clemson University.

14

Gross F., Lyon C., Persaud B., Srinivasan R. (2013), Safety Effectiveness of Converting Signalized Intersections to Roundabouts, Accident Analysis & Prevention, 50, 234-241.

10.1016/j.aap.2012.04.012
15

Gupta N., Johari M. U. M., Jashami H., Savolainen P. (2022), How is Traffic Safety Affected by Changes in Traffic Speeds Following Speed Limit Increases? An Evaluation with Probe Vehicle Data, Traffic Safety Research, 3, 000017.

10.55329/xsjw3584
16

Gyaase D., Newton S., Adams C. A., Enuameh Y., Adjei B. N., Nakua E. K. (2023), Effect of Speed Humps on Injury Consequences on Trunk Roads Traversing Towns in Ghana, Injury Prevention, 29(1), 68-73.

10.1136/ip-2022-04459836163153PMC9887354
17

Hauer E. (1997), Observational before/after Studies in Road Safety: Estimating the Effect of Highway and Traffic Engineering Measures on Road Safety.

18

Hayes A. F. (2018), Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-based Approach (2nd ed.), NW, Guilford Press.

19

Helm R., Mark A. (2012), Analysis and Evaluation of Moderator Effects in Regression Models: State of Art, Alternatives and Empirical Example, Review of Managerial Science, 6(4), 307-332.

10.1007/s11846-010-0057-y
20

Hong S. H., Jung S. (2014), Testing the Interaction Effects in Regression and Structural Equation Models: Theories and Procedures, The Korean Journal of Human Development, 21(4), 1-24.

10.15284/kjhd.2014.21.4.1
21

Hovey P. W., Chowdhury M. A. (2005), Development of Crash Reduction Factors, WS, Federal Highway Administration.

22

Jaccard J., Turrisi R. (2003), Interaction Effects in Multiple Regression (2nd ed.), CA, Sage Publications.

10.4135/9781412984522
23

Jami Ms. (2011), LED Traffic Signal Retrofits: Implications for Intersection Safety, Master’s Thesis, TN, The University of Memphis.

24

Jose P. E. (2013), Doing Statistical Mediation and Moderation, NW, Guilford Press.

25

Kelley J., Evans M. D. R., Lowman J., Lykes V. (2017), Group-mean-centering Independent Variables in Multi-level Models is Dangerous, Quality & Quantity, 51(1), 261-283.

10.1007/s11135-015-0304-z
26

Ki H. S., Kim E. C. (2023), A Study on the Influence of Triangular Islands on Intersection Traffic Crashes: Focusing on Incheon Metropolitan City, J. Korean Soc. Transp., 41(1), Korean Society of Transportation, 119-134.

10.7470/jkst.2023.41.1.119
27

Kim B. E., Lee Y. I. (2011), Impacts of Pre-signals on Traffic Crashes at 4-leg Signalized Intersections-Focusing on Four-way Intersections, Proceedings of the Korean ITS Fall Conference, 255-263.

28

KOROAD (2024a), Basic Improvement Plan and Effect Analysis for Traffic Accident Black Spots in 2024.

29

KOROAD (2024b), Estimation and Evaluation of Road Traffic Accident Costs in 2023.

30

Kwak K. Y. (2023), Statistical Analysis of Data with R.

31

Lee D. M., Kim D. H., Song K. S. (2011), A nalysis of Effects from Traffic Safety Improvement on Roadways using C-G Method, J. Korean Soc. Transp., 29(3), Korean Society of Transportation, 31-40.

32

Lee M. H., Choi K. J., Oh, I. S., Kim J. H. (2015), Analysis of Traffic Accident Reduction Performance of High-quality and Long-life Pavement Marking Materials, Journal of Civil and Environmental Engineering Research, 35(4), 921-929.

10.12652/Ksce.2015.35.4.0921
33

Liang Y., Yuan H., Wang Z., Wan Z., Liu T., Wu B., Chen S., Tang X. (2024), Nonlinear effects of traffic statuses and road geometries on highway traffic accident severity: A machine learning approach, PloS one, 19(11), e0314133.

10.1371/journal.pone.031413339576833PMC11584126
34

Lim J. S., Han S. J. (2024), Analysis of Safety Effects of Color Guide Markings at the At-Grade Intersection, Traffic Safety Research, 43(1), 155-174.

10.22940/TSR.2024.43.1.155
35

Ma J., Fontaine M. D., Zhou F., Hu J., Hale D. K., Clements M. O. (2016), Estimation of Crash Modification Factors For an Adaptive Traffic Signal Control System, Journal of Transportation Engineering, 142(12), American Society of Civil Engineers, 04016061.

10.1061/(ASCE)TE.1943-5436.0000890
36

Ma Y., Xu J., Gao C., Mu M., E G., Gu C. (2022), Review of Research on Road Traffic Operation Risk Prevention and Control, International Journal of Environmental Research and Public Health, 19(19), 12115.

10.3390/ijerph19191211536231418PMC9564786
37

Maeng G. Y. (2024), A Study on the Safety Effectiveness of Crash Improvement Projects at Black Spot Using Empirical Bayes Method, Master’s thesis, Myongji University.

10.7470/jkst.2024.42.6.649
38

Marzoug R., Echab H., Lakouari N., Ez-Zahraouy H. (2016), Car accidents at the Intersection with Speed Limit Zone and Open Boundary Conditions, In Cellular Automata: 12th International Conference on Cellular Automata for Research and Industry, ACRI 2016, Fez, Morocco, September 5-8, 2016, Proceedings 12, 303-311.

10.1007/978-3-319-44365-2_30
39

Merritt D. K., Lyon C., PersaudB., Torres H. N. (2020), Developing Crash-modification Factors for High-friction Surface Treatments, WS, Federal Highway Administration.

40

MOLIT (2024), Annual Report on Traffic Safety 2024.

41

Montella A. (2009), Safety Evaluation of Curve Delineation Improvements: Empirical Bayes Observational Before-and-After Study, Journal of the Transportation Research Board, 2103(1), 69-79.

10.3141/2103-09
42

Nishiuchi H., Dias C., Kawato S. (2023), Empirical Evaluation of Change in Crash Risk due to Lane Marking Reallocation: A Case Study in Kochi City, Japan, IATSS research, 47(4), 535-544.

10.1016/j.iatssr.2023.12.001
43

Nye T., Simpson C. (2024), Safety Evaluation of Dual Left-Turn Lane Installations in North Carolina, Journal of the Transportation Research Board, 2678(10), 1239-1251.

10.1177/03611981241236791
44

Obeidat M. S., Rys M. J. (2016), Intersection Lighting Impacts on Nighttime Crashes Reduction and Safety Improvement, TRB 2016 Annual Meeting, WA, NHYSA.

45

Park B. H. (2014), Analysis of Traffic Accident Reduction Effect Before and After Signal Operation System Improvement Projects, Journal of the Institute of Construction Technology, 33(2), 21-25.

46

Park G. Y., Kim T. H., Kim S. W., Lee S. B. (2006), Comparing the Effectiveness of Road Safety Features by Spatial Scope of Safety Improvement Project, J. Korean Soc. Transp., 24(4), Korean Society of Transportation, 31-42.

47

Park S. N., Im J. B., Kim D. I., Kim J. H., Choi M. H. (2016), Estimation of Traffic Accident Effectiveness of White Left Shoulder Line Using a Comparison Group Method, International journal of highway engineering, 18(5), 127-134.

10.7855/IJHE.2016.18.5.127
48

Park Y. W., Park S. H. (2021), Analysis on the Effect of Jaywalking Prevention Facilities Using Cluster Analysis and Empirical Bayes Method, Traffic Safety Research, 40, 123-133.

10.22940/TSR.2021.40.1.123
49

Pratelli A., Lupi M., Pratelli C., Farina A. (2020), Mini-roundabouts for Improving Urban Accessibility, In A. Sładkowski, Modelling of the Interaction of the Different Vehicles and Various Transport Modes, 333-382, Springer International Publishing.

10.1007/978-3-030-11512-8_8
50

Putra I. G. B., Kuo P.-F., Lord D. (2024), Estimating the Effectiveness of Marked Sidewalks: An Application of the Spatial Causality Approach, Accident Analysis & Prevention, 206, 107699.

10.1016/j.aap.2024.107699
51

Rahman M., Hoang-Tung N., Kojima A., Kubota H. (2017), Identification of External Factors Affecting the Effectiveness of Speed Humps, Journal of the Eastern Asia Society for Transportation Studies, 12, 2016-2034.

52

Retallack A. E., Ostendorf B. (2020), Relationship between Traffic Volume and Accident Frequency at Intersections, International journal of environmental research and public health, 17(4), 1393.

10.3390/ijerph1704139332098180PMC7068508
53

Reyad P., Sayed T., Essa M., Zheng L. (2022), Real-Time Crash-Risk Optimization at Signalized Intersections, Transportation Research Record: Journal of the Transportation Research Board, 2676(12), 32-50.

10.1177/03611981211062891
54

Rothman L., Macpherson A., Buliung R., Macarthur C., To T., Larsen K., Howard A. (2015), Installation of speed humps and pedestrian-motor vehicle collisions in Toronto, Canada: A quasi-experimental study, BMC Public Health, 15(1), 774.

10.1186/s12889-015-2116-426264227PMC4534084
55

Saeed W., Saleh M. S., Gull M. N., Raza H., Saeed R., Shehzadi T. (2024), Geometric Features and Traffic Dynamic Analysis on 4-leg Intersections, International Review of Applied Sciences and Engineering, 15(2), 171-188.

10.1556/1848.2023.00681
56

Severino A., Pappalardo G., Curto S., Trubia S., Olayode I. O. (2021), Safety Evaluation of Flower Roundabout Considering Autonomous Vehicles Operation, Sustainability, 13(18), 10120.

10.3390/su131810120
57

Stevanovic A., Stevanovic J., Kergaye C. (2013), Optimization of Traffic Signal Timings Based on Surrogate Measures of Safety, Transportation Research Part C, Emerging Technologies, 32, 159-178.

10.1016/j.trc.2013.02.009
58

Tang H., Gayah V. V., Donnell E. T. (2020), Crash modification Factors for Adaptive Traffic Signal Control: An Empirical Bayes before-after study, Accident Analysis & Prevention, 144, 10567.

10.1016/j.aap.2020.105672
59

Tilahun N. (2023), Safety Impact of Automated Speed Camera Enforcement: Empirical Findings Based on Chicago’s Speed Cameras, Journal of the Transportation Research Board, 2677(1), 1490-1518.

10.1177/03611981221104808
60

Valderrama S. L., Palacios M. S., Botello V. P., Perez-Barbosa D., Arrieta J. V., Kisner J., Adriazola-Steil C. (2024), On Speed Management, Public Health, and Risky Behaviors: Examining the Side Effects of Automated Speed-Enforcement Cameras on Traffic Crashes in Bogotá, Colombia, Journal of the Transportation Research Board, 2678(3), 590-600.

10.1177/03611981231182419
61

Vingilis E. (2016), Conceptual and Methodological Issues in Evaluations of Road Safety Countermeasures, Safety, 2(1), 8.

10.3390/safety2010008
62

Von Quintus H. L., Mergenmeier A. (2015), Case Study: Kentucky Transportation Cabinet’s High Friction Surface Treatment and Field Installation Program, WA, Federal Highway Administration.

63

Werner T. (2015), Do Speed Humps Help Reduce Vehicular Speeds, Volumes, and Motorist Accidents, Master’s Thesis, CA, San Jose State University.

64

White H. (1980), A Heteroskedasticity-consistent Covariance Matrix Estimator and a Direct Test for Heteroskedasticity, Econometrica, 48(4), 817-838.

10.2307/1912934
65

Williamson M., Lin P. (2023), Effectiveness of Contrast Markings on Roadways and Orange Markings in Work Zones, IN, Purdue University.

10.5703/1288284317683
66

Wu L., Lord D., Geedipally S. R. (2017), Developing Crash Modification Factors for Horizontal Curves on Rural Two-lane Undivided Highways using a Cross-sectional Study, Transportation Research Record, 2636(1), 53-61.

10.3141/2636-07
67

Yang R., Wang Z., Lin P.-S., Li X., Chen Y., Hsu P. P., Henry A. (2019), Safety Effects of Street Lighting on Roadway Segments: Development of a Crash Modification Function, Traffic Injury Prevention, 20(3), 296-302.

10.1080/15389588.2019.1573317
68

Yoon G. H., Baek S. H., Lee G. M., Choi B. H. (2017), Case Study on the Improvement of Vulnerable Section of Pedestrian Safety, The 76th Conference of KST, Korean Society of Transportation, 275-280.

69

Yoon Y. I. (2016), Estimation of Traffic Accident Reduction Effect on Road Safety Facilities, Master’s thesis, The University of Seoul.

70

Zhou Y., Himes S., Le T., Gooch J., Northup K., Pavao P. (2022), Safety Effectiveness of the Road Diet Treatment in Rhode Island, Transportation Research Record: Journal of the Transportation Research Board, 2676(7), 24-31.

10.1177/03611981221076433
71

Zlatkovic M. (2019), Development of Performance Matrices for Evaluating Innovative Intersections and Interchanges MPC-19-391, Mountain-Plains Consortium.

Information
  • Publisher :Korean Society of Transportation
  • Publisher(Ko) :대한교통학회
  • Journal Title :Journal of Korean Society of Transportation
  • Journal Title(Ko) :대한교통학회지
  • Volume : 44
  • No :2
  • Pages :161-183
  • Received Date : 2025-01-18
  • Revised Date : 2025-09-19
  • Accepted Date : 2025-11-24
  • DOI :https://doi.org/10.7470/jkst.2026.44.2.161
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