PowerPoint Presentation

WELCOMERTCCE-International Conference

PRESENTED BY:Swapnil Shukla Civil Engineering DepartmentNIT Raipur

Accelerated Safety Evaluation Technique for Road Intersection in Indian ScenarioGUIDED BY-Shri Sunny Deol G. Assist. Professor,NIT Raipur Introduction Problem Statement Objective of work Scope of work Literature review Study methodology Site introduction Conclusion References

CONTENTINTRODUCTIONSafety criteria at road intersection is adversely affected by heterogeneous traffic conditions with 50% contribution of total road accidents in India.

The safety performance of various types of intersections is assessed either by crash data or by conflict data analysis.

The safety performance of the road intersections is primarily dependent on the primary parameters such as number, frequency, and severity level of crashes corresponding to its location.

The safety criteria in each type of intersection is also governed by various secondary intrinsic properties such as geometrics, traffic and pavement surface characteristics, and road user characteristics etc.

PROBLEM STATEMENTPerformance assessment of road infrastructure like Signalized intersections, Roundabouts, interchanges, islands etc. is daunting task at heterogeneous traffic conditions.

There is a need for the quick safety assessment technique to identify the safety levels of various intersections

Categorize the intersections in the urban areas depending on the severity levels in order to optimize the usage of public funds.OBJECTIVE OF WORKDevelopment of quick and reliable safety evaluation technique.

Validation of the technique with the existing standard evaluation methodology

LITERATURE REVIEWThe reliability of crash or conflict data is questionable which eventually affects the accuracy levels of the analysis. Hence apart from the primary parameters, secondary parameters also suggests a quick reliable solution to the safety assessment of various types of intersection.

Numerous methodologies such as statistical modelling, micro simulation models, crash prediction models etc. have been adopted for the analysis of safety performance depending on the type of intersection and data availability.

The Traffic conflict technique (TCT) is an approach based on observable traffic conflict events in which two or more road users approach each other in time and space such that the risk of collision presents itself if their movements remain unchanged. Severity measures, such as time-to-collision (TTC), post-encroachment time (PET).`SCOPE OF WORKIntersection Inventory, Stated preference survey, and Traffic survey has been carried out for the selected five distinct types of intersections in the urban . The selection criteria of the intersection was based on the type of intersection, geometrics, traffic characteristics and types of risk factors involved. Stated preference survey has been carried out by taking expert group ranking based on the developed questionnaire form considering various risk factors affecting the intersection safety.

Framework and MethodologyINVENTORY ELEMENTS FOR PRACTICE

CALCULATION OF SAFETY HAZARDOUS INDEXSimilarly safety factor was estimated independently for each risk factor of the selected intersection by multiplying estimated risk factor index as discussed in Table 2 with assigned weight for that particular risk element as discussed in Fig.2. Therefore the final safety hazardous index (SHI) is estimated for each intersection is calculated by the following relationship as shown in Eq.1. The estimated SHI values varies from 0 to 1 scale which indicates severity level of intersection. Safety Hazardous Index =

Where, n= Total number of safety factors

HIERARCHY OF INTERSECTION SAFETY-ASSIGNED WEIGHT VALUES USING AHP AND EXPERT OPINIONCHECKLIST POINTS-EVALUATION

Analysis RESULTSEVALUATED RISK VALUES

Safety Hazardous IndexVALIDATION OF SAFETY HAZARDOUS INDEXThe developed SHI values for the selected intersections was validated with the results obtained from the crash data analysis and surrogate safety analysis. Crash data analysis has been carried out for all the intersections from the crash data obtained.

Surrogate safety analysis has been carried out based on the identified conflict points in each intersection.

Results obtained from the AHP, Crash data and Surrogate safety analysis techniques were compared and the correlation obtained is quite acceptable.

DATA VALIDATIONCONCLUSIONQuick and reliable safety performance evaluation technique for various types of intersections. The developed method is partially analytical and partially decision making (audit based) oriented. Can be used as a preliminary analysis technique for diagnosis the severity levels of various intersection in the urban area.

Limitations-

May not depict realistic results due to its user decision oriented nature.Developed technique also assists various stakeholders REFERENCEAmundsen, F., Hyden, C., Traffic Conflicts, In: Proceedings of First Workshop, Institute of Transport Economics, 1977, Oslo.Elvik, R., Effects on road safety of converting intersections to roundabouts: review of evidence from Non-U.S. studies, Transportation Research Record: Journal of the Transportation Research Board, vol. 1847, 2003, pp. 110. Gettman, D., Head, L., Surrogate Safety Measures from Traffic Simulation Models, In Transportation Research Record: Journal of the Transportation Research Board, Transportation Research Board of the National Academies, Washington, DC, vol. No. 1840, 2003, pp. 104115.Meeghat, H., et.al., Ranking of Hazardous Road Locations in Two-Lane Two-Way Rural Roads with No Crash Record, Australasian Transport Research Forum 2011 Proceedings, Adelaide, Australia, 2011.Minderhoud, M.M., Bovy, P.H.L., Extended time-to-collision measures for road traffic safety assessment,. Accident Analysis and Prevention, 2001. Vol. 33 (1), pp. 8997.Persaud, B., et.al, Safety effects of roundabout conversions in the United States: empirical Bayes observational before-and-after study, Transportation Research Record: Journal of the Transportation Research Board, vol. 1751, 2001 pp. 18.Saaty, T., Decision making for leaders, RWS Publications, 1990.

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