A Comparative Analysis Of Exit Ramp Terminal Design Practices To Deter Wrong-way Driving - PowerPoint Presentation

1. A Comparative Analysis Of Exit Ramp Terminal Design Practices To Deter Wrong-way Driving In Different StatesPresenter:Md AtiquzzamanGraduate Research AssistantHighway Research CenterAuburn University, Auburn, Alabama

2. OutlineObjectives and MotivationData CollectionComparative AnalysisConclusions2

3. Brief Introduction to Wrong-way Driving (WWD)Driving against the main direction of traffic flow, inadvertently or deliberately, on a controlled access highwayThree possible mechanisms to describe how a driver can end driving in the wrong direction (NTSB 2012):Entering the freeway through an exit rampMaking a U-turn on the mainlineUsing an emergency turnaround through the median3

4. Objectives and MotivationsConduct a comparative analysis of geometric features and TCDs usage at exit ramp terminals of full diamond and partial cloverleaf interchanges between two states (Alabama and Illinois)4Wrong-way driving (WWD) crashes (2009-2013)

5. Data Collection5

6. Geometric Data: Full Diamond Interchange6

7. Geometric Data: Partial Cloverleaf Interchange7

8. Traffic Control Devices Distance of WRONG WAY sign from crossroadUse of DO NOT INTER signIntersection signalizationPresence of retroreflective tape on sign postsWW Pavement arrow8One (right/left side of exit ramp)Two (channelizing island and right/left side of exit ramp)Two (both side of exit ramp)Three (channelizing island and both side of exit ramp)

9. DATAInterchange typeNo. of Exit Ramp TerminalsAlabamaIllinoisFull Diamond Interchange194362Partial Cloverleaf Interchange381149

10. 10Full Diamond Interchange

11. Intersection Angle: Full Diamond Interchange 11AlabamaIllinoisRecommended design: Right angleChi-square test results: X2 = 19.05; df = 2; p < 0.001

12. Median on Crossroad: Full Diamond Interchange 12AlabamaIllinoisRecommended design: Non-traversableChi-square test results: X2 = 80.12; df = 1; p < 0.001

13. Channelizing Island: Full Diamond Interchange 13AlabamaIllinoisRecommended design: Non-traversableChi-square test results: X2 = 90.27; df = 1; p < 0.001

14. Distance to Nearest Access Point: Full Diamond Interchange 14Recommended design: Minimum = 600 ft., desirable =1320 ft.Chi-square test results: X2 = 81.16; df = 4; p < 0.001

15. Tangency of Corner Radius: Full Diamond Interchange 15AlabamaIllinoisRecommended design: Non-tangent Chi-square test results: X2 = 33.57; df = 1; p < 0.001

16. Distance of WRONG-WAY Sign: Full Diamond Interchange 16Recommended design: No specific guidelines Chi-square test results: X2 = 344.09; df = 4; p < 0.001

17. Application of DNE Sign: Full Diamond Interchange 17Recommended design: At least one DNE sign Chi-square test results: X2 = 69.96; df = 3; p < 0.001

18. WW Arrow on Pavement: Full Diamond Interchange 18AlabamaIllinoisChi-square test results: X2 = 265.82; df = 1; p < 0.001

19. Two Sets of WW Sign Along the Exit Ramp: Full Diamond Interchange 19AlabamaIllinoisChi-square test results: X2 = 136.55; df = 1; p < 0.001

20. Reflective Tape on Sign Posts: Full Diamond Interchange 20AlabamaIllinois

21. 21Partial Cloverleaf Interchange

22. Intersection Angle: Partial Cloverleaf Interchange 22AlabamaIllinoisRecommended design: Right angleChi-square test results: X2 = 0.94; df = 2; p = 0.626

23. Corner Radius from Crossroad:Partial Cloverleaf Interchange23Recommended design: Maximum 80 ft.Chi-square test results: X2 = 0.34; df = 1; p = 0.56

24. Corner Radius to Crossroad:Partial Cloverleaf Interchange24Recommended design: Maximum 100 ft.Chi-square test results: X2 = 5.51; df = 1; p = 0.019

25. Median on Crossroad: Partial Cloverleaf Interchange 25Recommended design: Non-traversableChi-square test results: X2 = 14.08; df = 1; p <0.001

26. Width of Median between Exit and Entrance Ramp:Partial Cloverleaf Interchange26Recommended design: Minimum 50 ft.Chi-square test results: X2 = 17.09; df = 1; p < 0.001

27. Distance to Nearest Access Point:Partial Cloverleaf Interchange27Recommended design: Minimum = 600 ft., desirable =1320 ft.Chi-square test results: X2 = 2.83; df = 2; p = 0.24

28. Distance to First WW Sign from Crossroad:Partial Cloverleaf Interchange28Recommended design: No specific guidelines Chi-square test results: X2 = 45.06; df = 4; p < 0.001

29. Application of DNE Sign:Partial Cloverleaf Interchange29Recommended design: At least one DNE sign Chi-square test results: X2 = 31.52; df = 3; p < 0.001

30. WW Arrow on Pavement: Partial Cloverleaf Interchange 30Chi-square test results: X2 = 59.89; df = 1; p < 0.001

31. Two Sets of WW Sign Along the Exit Ramp: Partial Cloverleaf Interchange 31Chi-square test results: X2 = 28.91; df = 1; p < 0.001

32. Reflective Tape on Sign Posts: Partial Cloverleaf Interchange 32AlabamaIllinois

33. Conclusions and RecommendationsMajor differences in geometric features that might have resulted in relatively lower occurrences of WW entries in the exit ramp terminals of interchanges in Illinois:Non-traversable crossroad median Non-traversable channelizing island Access control within close proximity of interchange terminalsFor exit ramp terminals of full diamond interchanges, angular connection between left edge of exit ramp and right edge of crossroad (i.e., the corner radius is non-tangent to crossroad edge).Wider median width between exit and entrance ramps at partial cloverleaf interchanges.33

34. Conclusions and RecommendationsMajor differences in TCDs usage that might be potential factors for relatively lower occurrences of WW entries in the exit ramp terminals of interchanges in Illinois:Placement of WW signs within short distance from the crossroad Within 200 ft. for majority of the casesRed retroreflective tape on WW and DNE sign postsTwo sets of WW signs along the exit ramp terminalsWW arrow34

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