Pedestrian Guard Railing: A Review of Criteria for Installation by P. Zheng and R.D.Hall (Transportation Research Group) Contract No: 1505 This report has been produced by the Transportation Research Group (University of Southampton) for Transport for London. Any views expressed are not necessarily those of Transport for London. Pedestrian Guard Railing: A Review of Criteria for Installation FINAL REPORT to Transport for London Contract No: 1505 by P. Zheng and R.D.Hall Transportation Research Group University of Southampton October 2003 Transportation Research Group School of Civil Engineering and the Environment University of Southampton, Highfield, Southampton, SO17 1BJ Tel: 023 8059 2192 Fax: 023 8059 3152 email: [email protected] Web: www.trg.soton.ac.uk Pedestrian Guard Railing – A Review of Criteria for Installation CONTENTS LIST OF TABLES ................................................................................................... ii LIST OF FIGURES ................................................................................................. iii EXECUTIVE SUMMARY........................................................................................ v 1 INTRODUCTION ............................................................................................. 1 2 CURRENT GUIDELINES AND PRACTICE FOR INSTALLATION.................. 2 2.1 Introduction..........................................................................................................2 2.2 Guidelines on Installation.....................................................................................2 2.2.1 At Pedestrian Crossings ............................................................................2 2.2.2 At Intersections..........................................................................................3 2.2.3 At Other Places..........................................................................................4 2.2.4 Safety Audit ...............................................................................................4 2.2.5 Standard....................................................................................................4 2.2.6 Maintenance ..............................................................................................5 2.3 Interviews with Traffic Engineers .........................................................................5 3 RESEARCH ON THE SAFETY EFFECTS OF GUARD RAILING................... 6 3.1 Introduction..........................................................................................................6 3.2 MOLASSES Database.........................................................................................6 3.3 Wolverhampton Study .........................................................................................7 3.4 London Study ......................................................................................................7 3.5 Pelican Crossings Study......................................................................................8 3.6 Accident Modelling Studies..................................................................................8 3.7 Conclusion.........................................................................................................10 4 SITE SURVEY DATA COLLECTION ............................................................ 11 4.1 Site Selection.....................................................................................................11 4.2 Site Observations ..............................................................................................13 4.3 Accident Data Collection....................................................................................14 5 ANALYSIS ..................................................................................................... 15 5.1 Vehicle Attributes...............................................................................................15 5.2 Pedestrian Attributes .........................................................................................16 5.2.1 Pedestrian Conflict...................................................................................16 5.3 Overall Traffic Conditions at Surveyed Sites......................................................19 5.4 Overall Safety Effect of Guard Rail ....................................................................22 5.4.1 Accidents and Conflicts at Sites with/without Guard Rail by Type of Site .............................................................................................22 5.4.2 Comparing Site Types to the Overall Average .........................................23 5.5 Site Specific Effectiveness of Guard Rails .........................................................24 5.5.1 Pedestrian Crossings...............................................................................24 5.5.1.1 Behaviour Effect...........................................................................25 5.5.1.2 Safety Effect.................................................................................27 5.5.2 Junctions .................................................................................................28 5.5.2.1 Behaviour Effect...........................................................................29 5.5.2.2 Safety Effect ................................................................................31 i Pedestrian Guard Railing – A Review of Criteria for Installation 5.5.3 Links and Central Reservations ...............................................................31 5.5.3.1 Behaviour Effect...........................................................................33 5.5.3.2 Safety Effect ................................................................................34 5.5.4 Transportation Interchanges and Schools ................................................36 5.5.4.1 Behaviour Effect...........................................................................37 5.5.4.2 Safety Effect ................................................................................38 5.6 Effects of Traffic Conditions and Pedestrian Behaviour on Safety......................39 5.7 Conclusions.......................................................................................................41 ACKNOWLEDGEMENTS ..................................................................................... 42 REFERENCES ...................................................................................................... 43 APPENDIX A: SPEED MEASUREMENT FROM VIDEO RECORDING................ 45 A.1 Method.......................................................................................................... …45 A.2 Measurement Error............................................................................................... 46 APPENDIX B: PEDESTRIAN CONFLICTS........................................................... 49 B.1 Overview ...........................................................................................................49 B.2 Definition...........................................................................................................49 B.2.1 General Definition.....................................................................................49 B.2.2 Operational Definition ...............................................................................50 B.3 Conflict Identification .........................................................................................54 APPENDIX C: SITE INFORMATION..........................................................……….57 LIST OF TABLES Table 3.1 Before-after Accidents at 20 Sites from MOLASSES Database ............... 6 Table 3.2 Wolverhampton Road Safety Plan: 1996-99 3rd Review ......................... 7 Table 4.1 Desired Number of Sites for Behaviour Study.......................................... 11 Table 4.2 Summary of Selected Survey Sites ........................................................ 12 Table 5.1 Traffic Conditions at Sites Without Railing ............................................... 21 Table 5.2 Traffic Conditions at Sites With Railing .................................................... 21 Table 5.3 Traffic and Pedestrian Attributes at Pedestrian Crossing Sites ................ 26 Table 5.4 Correlation Coefficients (Pedestrian Crossings) ...................................... 27 Table 5.5 Traffic and Pedestrian Attributes at Junction Sites................................... 29 Table 5.6 Correlation Coefficients (Junctions) ......................................................... 30 Table 5.7 Traffic and Pedestrian Attributes at Link and Central Reservation Sites... 33 Table 5.8 Traffic and Pedestrian Attributes at Transportation Interchange and School Sites ..................................................................................... 38 Table 5.9 Correlation Coefficients between Safety and Traffic Attributes................. 38 Table 5.10 Correlation Coefficients between Safety and Behavioural Attributes........ 40 ii Pedestrian Guard Railing – A Review of Criteria for Installation LIST OF FIGURES Figure 3.1 Diagram of a Three-arm Junction ........................................................... 9 Figure 4.1 Snapshot of a Video Image (Site IP02).................................................... 13 Figure 5.1 Reference Lines used for Speed Measurement....................................... 16 Figure 5.2 Operational Definition of Conflict ...........................................................