Options/Feasibility Study for the A23/A232 Fiveways Scheme Transport for London 18 December 2013 Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme Notice This document and its contents have been prepared and are intended solely for Transport for London’s information and use in relation to the Options/feasibility study for the A23/A232 Fiveways scheme. Atkins Highways & Transportation assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents. This document has 70 pages including the cover. Document history Job number: 5127130 Document ref: 5127130/FS/REP/001 Revision Purpose description Originated Checked Reviewed Authorised Date - Draft issue 05/12/13 A Final Issue 19/12/13 Client signoff Client Transport for London Project Fiveways Junction Improvement Document title Options/feasibility study for the A23/A232 Fiveways scheme Job no. 5127130 Copy no. Document 5127130/FS/REP/001 Rev A reference Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme Table of contents Chapter Pages Executive summary 5 1. Introduction 6 1.1. Client Brief 6 1.2. Aims of the Study 6 1.3. Background 6 1.4. Proposed Options 6 2. Existing Information 8 2.1. Location 8 2.2. Road Layout 8 2.3. Bridge Records 9 2.4. As Built Drawings 9 2.5. Health and Safety 9 2.6. Environment 9 2.7. Traffic 9 2.8. Accident Data 10 2.9. Statutory Undertakers Equipment 10 2.10. Network Rail Equipment / Geometry 10 2.11. Land Ownership 11 2.12. Geotechnical Information 11 2.13. Topographical Information 11 2.14. Drainage Details 11 3. General Design Constraints 12 3.1. Highways General Design Principles 12 3.2. Design Life 12 3.3. Design Speed 12 3.4. Cross Section 13 3.5. Horizontal Alignment 14 3.6. Vertical Alignment 16 3.7. Visibility 16 3.8. Loading 17 3.9. Vertical Clearance 17 3.10. Railway Lateral Clearance 17 3.11. Road Restraint Systems 17 3.12. Statutory Undertakers Equipment 18 3.13. Temporary Works/Traffic Management 18 3.14. Network Rail 21 3.15. Other Stakeholders 21 3.16. Architecture and Finishes 21 4. Highways Design Option Development 22 4.1. Existing Topography 22 4.2. Option 1 Parameters 23 4.3. Option 1A Parameters 26 4.4. Option 2 Parameters 29 5. Structural Design Option Development 30 5.1. Structural Attributes 30 5.2. Construction Sequence 33 Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme 5.3. Network Rail Consultation 33 6. Appraisal of Options 35 6.1. Description of Viable Options 35 6.2. Estimated Initial Capital Costs 44 6.3. Whole Life Costs 45 6.4. Outline Construction Programme 45 6.5. Key Risks 45 6.6. Departures from Standard 46 6.7. Advantages and Disadvantages 46 7. Health and Safety Considerations 50 8. Environmental Considerations 51 8.1. Potential Ecological Constraints 51 8.2. Environmental Management Plans 57 9. Conclusions 58 10. Recommendations 58 Appendices 59 Appendix A. Existing Bridge Record Information 60 Appendix B. Existing Statutory Undertaker’s Information 61 Appendix C. Drawings 62 Appendix D. Outline Design Programme 63 Appendix E. Outline Construction Programme 64 Appendix F. Project Risk Register 65 Appendix G. Designers’ Risk Assessment 66 Appendix H. Environmental Management Plans and Ecology Calendar 67 Appendix I. Topographical Survey Specification and Extent 68 Tables Table 3-1 Details of Proposed cross section 13 Table 3-2 Details of SSD for a 50kph urban design 16 Table 5-1 Information to be requested from Network Rail 34 Table 6-1 Construction Period and Railway Possessions 45 Figures Figure 2-1 Location Plan 8 Figure 3-1 Extract from TD 9/93 showing geometric parameters for a 50kph design speed 15 Figure 3-2 Typical Reinforced concrete H4a Parapet 18 Figure 4-1 Extract from TD 41/95 of a simple layout for a private access 24 Figure 4-2 Diverge Slip Road layouts 25 Figure 4-3 Diverge Slip Road dimensions 25 Figure 4-4 Merge Slip Road layouts 27 Figure 4-5 Merge Slip Road dimensions 27 Figure 4-6 TD 27/05 Slip Road Cross Section Details 28 Figure 6-1 Existing South Abutment and central trestle showing clearance to track 37 Figure 6-2 Existing North Abutment and adjacent platform 37 Figure 6-3 High Meads loop Construction 39 Figure 6-4 River Worth Keighley Construction 39 Figure 6-5 Wooferton Bridge Construction 40 Figure 6-6 Typical Piling Rig Layout 40 Figure 6-7 View of Existing Waddon Bridge from the station 41 Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme Executive summary Transport for London (TfL) is planning a scheme in the vicinity of Croydon’s Fiveways junction to improve capacity at the junction and support new developments in the wider area. This feasibility study considers three options, which were put forward by TfL, appraising the different variations within the options and this report provides the following deliverables for each option: Concept designs including any structural solution options; Structural design programme; Buildability risks and issues; Phasing of the works and buildability programme; Temporary works including traffic management; Recommendations In the absence of detailed costing for each of the options, together with the fact that traffic surveys and modelling have not been carried out, it is not possible to selected a preferred option for the scheme. Section 6.7 of this report discusses the advantages and disadvantages of each option. This discussion, together with cost analysis and traffic modelling will allow a reasoned comparison of the various options to be made, and will allow a preferred option to be selected. It is recommended that the additional required information discussed above, together with other recommendations discussed in section 9, is carried out in advance of the detailed design phase. Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme 1. Introduction 1.1. Client Brief Atkins has been commissioned by Transport for London (TfL) to undertake the feasibility study for the A23/A232 Fiveways scheme in accordance with its brief included in Tender Ref: tfl_scp_000027_task_24_co057. 1.2. Aims of the Study As stated in the client brief, the objective of the feasibility study is to consider three options, which were put forward by TfL, appraising the different variations within the options. This report provides the following deliverables for each option: Concept designs including any structural solution options; Structural design programme; Buildability risks and issues; Phasing of the works and buildability programme; Temporary works including traffic management; Recommendations 1.3. Background Fiveways junction in Croydon is a signalised junction between a number of roads – the A23 Purley Way to the north and south, the A232 Stafford Road to the north east, the B275 Denning Avenue to the east and the B271 Stafford Road to the south west. The junction is over-capacity, and traffic regularly builds up in the vicinity of the junction. The objective of the options proposed for this feasibility study is to alleviate the traffic feeding into the Fiveways junction. 1.4. Proposed Options The issues at Fiveways junction have been under investigation for some time, and TfL have developed two options to undertake feasibility and to undertake an analysis of the benefits of each option. The options considered are as follows: 1.4.1. Option 1 (and 1A): Elevated Link Road (ELR) connecting A232 Croydon Road and A232 Duppas Hill Road These options would keep both east and west-bound traffic on the A232 away from the Fiveways junction and any parallel running on the A23. The elevated section will run over the railways line and also cross the existing junction between the A232 Duppas Hill Road and the A232 Stafford Road. Option 1 takes the most direct route linking the A232, whereas The alignments for these options will be evaluated. The ELR will include a multi-span bridge. TfL has expressed aspirations to utilise, where appropriate, the spaces below the proposed bridge spans for commercial or private use purposes. Alternative structural solutions will be considered and the advantages and disadvantages of their attributes in the context of this feasibility study will be discussed. Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme 1.4.2. Option 2: Waddon Bridge replacement and widening of Epsom Road for two-way traffic This option proposes to replace the existing Waddon Station Bridge over the railway with a new replacement wider bridge. This is intended to provide more carriageway lanes and allow more traffic capacity on this short critical link where it carries both A23 and A232 traffic. Epsom Road is also proposed to be widened to allow a new two-way operation. This removes the need for Eastbound A232 traffic to use the Fiveways junction. Atkins Version 1.0 | 18 December 2013 Options/Feasibility Study for the A23/A232 Fiveways Scheme 2. Existing Information 2.1. Location Fiveways junction in Croydon is a junction between a number of roads – the A23 Purley Way to the north and south, the A232 Stafford Road to the north east, the B275 Denning Avenue to the east and the B271 Stafford Road to the south west. Fiveways Junction Figure 2-1 Location Plan 2.2. Road Layout The A23 road runs north-south providing a link between the M25/M23 and Kennington Park/Oval. The A23 passes to the west of Croydon, adjacent to Waddon Railway Station.