This study aims to develop safety performance functions (SPFs) and crash modification factors (CMFs) for the safety assessment of roundabouts as a whole and their components, especially at entry, exit, and circulating lanes. This study uses historical crash data collected over five years (2015–2019) from 21 roundabouts (78 approaches) situated in some of the major cities in India. SPF and CMF models were developed using negative binomial and cross-sectional approaches. Results show that the percentage of motorized two-wheelers, average daily traffic, central island diameter, entry angle, weaving width, departure width, number of lanes at approach, exit angle, exit width, posted speed limit, weaving length, circulating roadway width, road surface condition, number of circulatory lanes, central island height, and number of legs contribute to the crash occurrence in the roundabout vicinity. In addition to this, circulating roadway width, average daily traffic, and posted speed limit are the most influencing risk factors across the entire roundabout vicinity. Furthermore, an interesting fact is that, given the asymmetrical impact of geometric and traffic factors, the overall crash rate varies across roundabout segments. The findings of this study may be useful for updating the current design guidelines for roundabouts, considering the safety perceptive. Besides, the proposed SPF and CMF tools could be used to investigate the likelihood of crashes at roundabouts. Moreover, this model would help safety experts to implement adequate safety treatment in the vicinity of roundabouts under heterogenous non-lane-based traffic conditions.
RettingR. A.PersaudB. N.GarderP. E.LordD.Safety Effect of Roundabout Conversions in the United States: Empirical Bayes Observational Before-After Study. Transportation Research Record: Journal of the Transportation Research Board, 2001. 1751: 1–8. https://doi.org/10.3141/1751-01
4.
ElvikR.Assessing the Validity of Road Safety Evaluation Studies by Analysing Causal Chains. Accident Analysis and Prevention, Vol. 35, No. 5, 2003, pp. 741–748. https://doi.org/10.1016/S0001-4575(02)00077-5
5.
GuichetB.Transportation Research Circular E-C083: Evolution of Roundabouts in France and New Uses. Transportation Research Board, Washington, D.C., 2005.
6.
RodegerdtsL.MirandaB.WempleE.MyersE.KyteM.DixonM. P.ListG. F., et al. Appendixes to NCHRP Report 572: Roundabouts in the United States. Transportation Research Board, Washington, D.C., 2007.
7.
IsebrandsH.Crash Analysis of Roundabouts at High-Speed Rural Intersections. Transportation Research Record: Journal of the Transportation Research Board, 2009. 2096: 1–7. https://doi.org/10.3141/2096-01
8.
MontellaA.Identifying Crash Contributory Factors at Urban Roundabouts and Using Association Rules to Explore Their Relationships to Different Crash Types. Accident Analysis and Prevention, Vol. 43, No. 4, 2011, pp. 1451–1463. https://doi.org/10.1016/j.aap.2011.02.023
9.
Indian Highway Capacity Manual (Indo-HCM). CSIR Central Road Research Institute, New Delhi, 2017.
10.
Indian Roads Congress (IRC-65). Guidelines for Planning and Design of Roundabouts, 1st rev. New Delhi, 2017.
11.
SonuM.DhamaniyaA.ArkatkarS.JoshiG.Time Occupancy as Measure of PCU at Four Legged Roundabouts. Transportation Letters, 2016, pp. 1–12. https://doi.org/10.1080/19427867.2016.1154685
12.
Highway Capacity Manual 2010. Transportation Research Board, National Research Council, Washington, D.C., 2010.
13.
VinayarajV. S.PerumalV.Safety Evaluation of Urban Roundabouts in India: A Safety Performance Function-Based Approach. Traffic Safety Research, Vol. 3, 2022, p. 000015. https://doi.org/10.55329/bylj4120
14.
CharlyA.MathewT. V.Estimation of traffic conflicts using precise lateral position and width of vehicles for safety assessment. Accident Analysis & Prevention, Vol. 132, 2019, p. 105264. https://doi.org/10.1016/j.aap.2019.105264
15.
FergusonE.BonnesonJ.RodegerdtsL.FosterN.PersaudB.LyonC.RhoadesD.NCHRP Research Report 888: Development of Roundabout Crash Prediction Models and Methods. Transportation Research Board, Washington, D.C., 2019.
16.
Highway Safety Manual 2010. American Association of State Highways and Transportation Officials, Washington, D.C., 2010.
17.
ArndtO.TroutbeckR. J.Transportation Research Circular E-C003: Relationship Between Roundabout Geometry and Accident Rates, Vol. 2. Transportation Research Board, Washington, D.C., 1998.
18.
KennedyJ.PeirceJ.SummersgillI.Transportation Research Circular E-C083: Review of Accident Research at Roundabouts. Transportation Research Board, Washington, D.C., 2005.
19.
MaycockG.HallR. D.Accidents at 4-Arm Roundabouts. Laboratory Report – UK Transport & Road Research Laboratory, LR 1120. Transport Research Laboratory, Wokingham, UK, 1984.
20.
WongS. C.SzeN. N.LiY. C.Contributory Factors to Traffic Crashes at Signalized Intersections in Hong Kong. Accident Analysis and Prevention, Vol. 39, No. 6, 2007, pp. 1107–1113. https://doi.org/10.1016/j.aap.2007.02.009
21.
YanX.RadwanE.Abdel-AtyM.Characteristics of Rear-End Accidents at Signalized Intersections Using Multiple Logistic Regression Model. Accident Analysis and Prevention, Vol. 37, No. 6, 2005, pp. 983–995. https://doi.org/10.1016/j.aap.2005.05.001
22.
KumaraS. S. P.ChinH. C.Modeling Accident Occurrence at Signalized Tee Intersections with Special Emphasis on Excess Zeros. Traffic Injury Prevention, Vol. 4, No. 1, 2003, pp. 53–57. https://doi.org/10.1080/15389580309852
23.
HarwoodD.CouncilF.HauerE.HughesW.VogtA.Prediction of the Expected Safety Performance of Rural Two-Lane Highways. Report No. FHWA-RD-99-207. Federal Highway Administration, 2000.
AnjanaS.AnjaneyuluM. V. L. R.Development of Safety Performance Measures for Urban Roundabouts in India. Journal of Transportation Engineering, Vol. 141, No. 1, 2015, p. 04014066. https://doi.org/10.1061/(ASCE)TE.1943-5436.0000729
26.
NovákJ.AmbrosJ.FričJ.How Roundabout Entry Design Parameters Influence Safety. Transportation Research Record: Journal of the Transportation Research Board, Vol. 2672, No. 34, 2018, pp. 73–84. https://doi.org/10.1177/0361198118776159.
27.
RodegerdtsL. A.BansenJ.TieslerC.KnudsenJ.MyersE. J.JohnsonM. T.MouleM., et al. NCHRP Report 672: Roundabouts: An Informational Guide, 2nd ed.Transportation Research Board, Washington, D.C., 2010.
28.
BagdadeJ.PersaudB. N.McIntoshK.YassinJ.LyonC. A.RedingerC.WhittenJ.ButchW. A.Evaluating the Performance and Safety Effectiveness of Roundabouts. Report No. RC-1566. Michigan Department of Transportation, Lansing, MI, 2011.
29.
KimS.ChoiJ.Safety Analysis of Roundabout Designs Based on Geometric and Speed Characteristics. KSCE Journal of Civil Engineering, Vol. 17, No. 6, 2013, pp. 1446–1454. https://doi.org/10.1007/s12205-013-0177-4
30.
DixonK.ZhengJ.Developing Safety Performance Measures for Roundabout Applications in the State of Oregon. Final Report, SPR 733. Oregon Department of Transportation, Salem, OR, Federal Highway Administration, Washington, D.C., 2013.
31.
KamlaJ.ParryT.DawsonA.Roundabout Accident Prediction Model Random-Parameter Negative Binomial Approach. Transportation Research Record: Journal of the Transportation Research Board, 2016. 2585: 11–19. https://doi.org/10.3141/2585-02
32.
Al-MarafiM. N.SomasundaraswaranK.AyersR.Developing Crash Modification Factors for Roundabouts Using a Cross-Sectional Method. Journal of Traffic and Transportation Engineering (English Edition), Vol. 7, No. 3, 2020, pp. 362–374. https://doi.org/10.1016/j.jtte.2018.10.012
33.
GrossF.PersaudB.LyonC.A Guide to Developing Quality Crash Modification Factors. FHWA-SA-10-032. U.S. Department of Transportation, Federal Highway Administration, Washington, D.C., 2010.
34.
MandavilliS.McCarttA. T.RettingR. A.Crash Patterns and Potential Engineering Countermeasures at Maryland Roundabouts. Traffic Injury Prevention, Vol. 10, No. 1, 2009, pp. 44–50.
35.
PoldersE.DanielsS.CastersW.BrijsT.Identifying Crash Patterns on Roundabouts. Traffic Injury Prevention, Vol. 16, No. 2, 2015, pp. 202–207. https://doi.org/10.1080/15389588.2014.927576
36.
HauerE.Observational Before/After Studies in Road Safety. Estimating the Effect of Highway and Traffic Engineering Measures on Road Safety. Emerald Group Publishing Limited, 1997.
37.
BonnesonJ. A.Zimmerman.K.Procedure for Using Accident Modification Factors in the Highway Design Process. Rep. 0-4703-P5. Texas Transportation Institute, Texas A&M University System, 2007.
38.
HauerE. Even Perfect Regressions May Not Tell the Effect of Interventions. Presented at 92nd Annual Meeting of the Transportation Research Board, Washington, D.C., 2013. https://trid.trb.org/view/1242624
39.
ShahdahU.SaccomannoF.PersaudB.Integrated Traffic Conflict Model for Estimating Crash Modification Factors. Accident Analysis and Prevention, Vol. 71, 2014, pp. 228–235. https://doi.org/10.1016/j.aap.2014.05.019
40.
BaharG.Transportation Research Circular E-C142: Methodology for the Development and Inclusion of Crash Modification Factors in the First Edition of the Highway Safety Manual. Transportation Research Board, Washington, D.C., 2010.
41.
LiX.LordD.ZhangY.Development of Accident Modification Factors for Rural Frontage Road Segments in Texas Using Generalized Additive Models. Journal of Transportation Engineering, Vol. 137, No. 1, 2011, pp. 74–83. https://doi.org/10.1061/ASCETE.1943-5436.0000202
42.
OhJ.ParkD.Analysis on Crash Reduction Factors for Road Segment Safety. International Journal of Urban Sciences, Vol. 18, No. 3, 2014, pp. 396–403. https://doi.org/10.1080/12265934.2014.955124
43.
PersaudB.LanB.LyonC.BhimR.Comparison of Empirical Bayes and Full Bayes Approaches for Before-After Road Safety Evaluations. Accident Analysis and Prevention, Vol. 42, No. 1, 2010, 38–43. https://doi.org/10.1016/j.aap.2009.06.028
HarperN. J.DunnR.Accident Prediction Models at Roundabouts. Presented at 75th ITE Annual Meeting and Exhibit Compendium of Technical Papers Institute of Transportation Engineers (ITE), Melbourne, Victoria, Australia, 2005.
46.
ParkJ.Abdel-AtyM.WangJ. H.LeeC.Assessment of Safety Effects for Widening Urban Roadways in Developing Crash Modification Functions Using Nonlinearizing Link Functions. Accident Analysis and Prevention, Vol. 79, 2015, pp. 80–87. https://doi.org/10.1016/j.aap.2015.03.025
47.
WuL.LordD.Investigating the Influence of Dependence between Variables on Crash Modification Factors Developed Using Regression Models. Presented at 95th Annual Meeting of Transportation Research Board, Washington, D.C., 2016.
48.
WoodJ. S.DonnellE. T.PorterR. J.Comparison of Safety Effect Estimates Obtained from Empirical Bayes Before-After Study, Propensity Scores-Potential Outcomes Framework, and Regression Model with Cross-Sectional Data. Accident Analysis and Prevention, Vol. 75, 2015, pp. 144–154. https://doi.org/10.1016/j.aap.2014.11.019
49.
ElvikR.Developing an Accident Modification Function for Speed Enforcement. Safety Science, Vol. 49, No. 6, 2011, pp. 920–925. https://doi.org/10.1016/j.ssci.2011.02.016
50.
GrossF.DonnellE. T.Case-Control and Cross-Sectional Methods for Estimating Crash Modification Factors: Comparisons from Roadway Lighting and Lane and Shoulder Width Safety Effect Studies. Journal of Safety Research, Vol. 42, No. 2, 2011, pp. 117–129. https://doi.org/10.1016/j.jsr.2011.03.003
51.
SacchiE.SayedT.El-BasyounyK.Collision Modification Functions: Incorporating Changes Over Time. Accident Analysis and Prevention, Vol. 70, 2014, pp. 46–54. https://doi.org/10.1016/j.aap.2014.03.003
52.
PandeA.ChandS.SaxenaN.DixitV.LoyJ.WolshonB.KentJ. D.A Preliminary Investigation of the Relationships between Historical Crash and Naturalistic Driving. Accident Analysis and Prevention, Vol. 101, 2017, pp. 107–116. https://doi.org/10.1016/j.aap.2017.01.023
53.
Abdul MananM. M.JonssonT.VárhelyiA.Development of a Safety Performance Function for Motorcycle Accident Fatalities on Malaysian Primary Roads. Safety Science, Vol. 60, 2013, pp. 13–20. https://doi.org/10.1016/j.ssci.2013.06.005
54.
LordD.ManneringF.The Statistical Analysis of Crash-Frequency Data: A Review and Assessment of Methodological Alternatives. Transportation Research Part A: Policy and Practice, Vol. 44, No. 5, 2010, pp. 291–305. https://doi.org/10.1016/j.tra.2010.02.001
AkaikeH.A New Look at the Statistical Model Identification. IEEE Transactions on Automatic Control, Vol. 19, No. 6, 1974, pp. 716–723. https://doi.org/10.1109/TAC.1974.1100705
57.
WashingtonS. P.KarlaftisM. G.ManneringF. L.Statistical and Econometric Methods for Transportation Data Analysis. CRC Press, New York, NY, 2011.
58.
CafisoS.Di GrazianoA.Di SilvestroG.La CavaG.PersaudB.Development of Comprehensive Accident Models for Two-Lane Rural Highways Using Exposure, Geometry, Consistency and Context Variables. Accident Analysis and Prevention, Vol. 42, No. 4, 2010, pp. 1072–1079. https://doi.org/10.1016/j.aap.2009.12.015
59.
YoungJ.ParkP. Y.Benefits of Small Municipalities Using Jurisdiction-Specific Safety Performance Functions Rather than the Highway Safety Manual’s Calibrated or Uncalibrated Safety Performance Functions. Canadian Journal of Civil Engineering, Vol. 40, No. 6, 2013, pp. 517–527. https://doi.org/10.1139/cjce-2012-0501
60.
Indian Roads Congress (IRC-70). Guidelines on Regulation and Control of Heterogeneous Traffic in Urban Areas, 1st rev. New Delhi, 2017.
61.
BrudeU.What Roundabout Design Provides the Highest Possible Safety. Nordic Road and Transport Research, Vol. 12, No. 2, 2000, pp. 17–21.
62.
Abdel-AtyM. A.LeeC.ParkJ.WangJ. H.AbuzwidahM.Al-ArifiS.Validation and Application of Highway Safety Manual (part D) in Florida. No. BDK78-977-14. Florida Department of Transportation, 2014.
63.
HarkeyD. L.Accident Modification Factors for Traffic Engineering and ITS Improvements, Vol. 617. Transportation Research Board, Washington, D.C., 2008.
64.
SteynH. J.GriffinA.RodegerdtsL. A.Accelerating Roundabouts in the United States: Volume IV of VII–A Review of Fatal and Severe Injury Crashes at Roundabouts. FHWA-SA-15-072. Federal Highway Administration, Washington, D.C., 2015.
65.
VenthuruthiyilS. P.ChunchuM.Anticipated Collision Time (ACT): A Two-Dimensional Surrogate Safety Indicator for Trajectory-Based Proactive Safety Assessment. Transportation Research Part C: Emerging Technologies, Vol. 139, 2022, p. 103655.
66.
AbhignaD.KondreddyS.Ravi ShankarK. V. R.Effect of Vehicle Composition and Delay on Roundabout Capacity Under Mixed Traffic Conditions. Archives of Transport, Vol. 40, 2016, pp. 7–14.
67.
PulvirentiG.DistefanoN.LeonardiS.TollazziT.Are Double-Lane Roundabouts Safe Enough? A CHAID Analysis of Unsafe Driving Behaviors. Safety, Vol. 7, No. 1, 2021, p. 20.
68.
SrinivasanR.GrossF.LyonC.PersaudB.EcclesK.HamidiA.BaekJ.SmithS.LeflerN.SundstromC.CarterD.NCHRP Report 705: Evaluation of Safety Strategies at Signalized Intersections. Transportation Research Board of the National Academies, Washington, D.C., 2011.
69.
MontellaA.TurnerS.ChiaradonnaS.AldridgeD.International Overview of Roundabout Design Practices and Insights for Improvement of the Italian Standard. Canadian Journal of Civil Engineering, Vol. 40, No. 12, 2013, 1215–1226.
70.
KennedyJ.PeirceJ.SummergrillI.International Comparison of Roundabout Design Guidelines. In 3rd International Symposium on Highway Geometric Design, Chicago, IL, 2005. https://trid.trb.org/view/760485.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
