VOLUME 7 PAVEMENT DESIGN AND …

1 July 2015 DESIGN MANUAL FOR ROADS AND BRIDGESVOLUME 7 pavement design and MAINTENANCESECTION 3 PAVEMENT maintenance ASSESSMENTPART 1HD 28/15 SKIDDING RESISTANCESUMMARYThe purpose of this document is to describe how the provision of appropriate levels of skid resistance on the UK strategic road network will be managed. This document describes how measurements of skid resistance are to be made and interpreted and is complemented by HD36 (DMRB ), which sets out advice on surfacing material characteristics necessary to deliver the required skid resistance FOR USE 1. This document supersedes HD 28/04, which is now withdrawn. It also supersedes IAN 98/07 and IAN 49 Remove existing Contents page for VOLUME 7 and insert new Contents page for VOLUME 7 dated July Remove HD 28/04, which is superseded by HD 28/15, and archive as appropriate4.

2 Insert HD 28/15 in VOLUME 7, section 3, Part Please archive this sheet as : A quarterly index with a full set of VOLUME Contents Pages is available separately from The Stationery Office Ltd. Printed with the permission of Highways England under licence from the Office of Public Sector Information. Crown Copyright 2015. All rights reserved. Copyright in the typographical arrangement and DESIGN is vested in the Crown. Applications for reproduction should be made in writing to the Licencing Department, Office of Public Sector Information, Information Policy Team, Kew, Richmond, Surrey TW9 4DU or ISBN 9780115534119 Standing Order Service Are you making full use of our standing order service?

3 The Standing Order Service is a free monitoring of the publications of your choice from over 4,000 classifications in 30 major subject areas. We send your books as they are published along with an invoice. With a standing order for class you can be supplied automatically with future titles for VOLUME 7 or for this and all other Roads and Bridges titles as they are published. The benefits to you are: Automatic supply of your choice of classification on publication No need for time-consuming and costly research, telephone calls and scanning of daily publication lists Saving on the need and the costs of placing individual orders We can supply a wide range of publications on standing order, from individual annual publications to all publications on a selected subject.

4 If you do not already use this free service, or think you are not using it to its full capacity, why not contact us and discuss your requirements? You can contact us at: The Stationery Office Standing Order Department PO Box 29 St. Crispins Duke Street Norwich Norfolk NR3 1GN Telephone 0333 202 5070; Fax 0333 202 5080 Online: We look forward to hearing from you. Printed in the United Kingdom for The Stationery Office P002739371 07/15 DESIGN MANUAL FOR ROADS AND BRIDGESS kidding ResistanceSummary: The purpose of this document is to describe how the provision of appropriate levels of skid resistance on the UK strategic road network will be managed.

5 This document describes how measurements of skid resistance are to be made and interpreted and is complemented by HD36 (DMRB ), which sets out advice on surfacing material characteristics necessary to deliver the required skid resistance ENGLANDTRANSPORT SCOTLANDWELSH GOVERNMENTLLYWODRAETH CYMRUTHE DEPARTMENT FOR REGIONAL DEVELOPMENTNORTHERN IRELANDHD 28/15 VOLUME 7, section 3,Part 1C MHDHAIL ALBAB uidheann le Riaghaltas na h-AlbaJuly 2015 Registration of AmendmentsVolume 7 section 3 Part 1 HD 28/15 Amend NoPage NoSignature & Date of incorporation of amendmentsAmend NoPage NoSignature & Date of incorporation of amendmentsREGISTRATION OF AMENDMENTSJuly 2015 Registration of AmendmentsVolume 7 section 3 Part 1 HD 28/15 Amend NoPage NoSignature & Date of incorporation of amendmentsAmend NoPage NoSignature & Date of incorporation of amendmentsREGISTRATION OF AMENDMENTSJuly 2015 DESIGN MANUAL FOR ROADS AND BRIDGESVOLUME 7 pavement design and MAINTENANCESECTION 3 PAVEMENT maintenance ASSESSMENTPART

6 1HD 28/15 SKIDDING RESISTANCEC ontentsChapter1. Introduction2. Operation3. Measurement of skid resistance4. Setting the Investigatory Level5. Initial investigation6. Detailed site investigation and prioritisation7. Use of slippery road warning signs8. References9. EnquiriesAnnexesAnnex 1 Background information on the measurement and interpretation of skid resistanceAnnex 2 Single Annual Skid Survey (SASS) approach to calculation of CSCA nnex 3 Benchmark sites approach to calculation of CSCA nnex 4 Calculation of Mean Summer Skid Coefficient (MSSC)Annex 5 Application of site categories and Investigatory LevelsAnnex 6 Site investigation report templateJuly 2015 DESIGN MANUAL FOR ROADS AND BRIDGESA nnex 7 Procedure for identifying sites requiring detailed investigationAnnex 8 Glossary of TermsJuly 20151/1 Chapter 1 IntroductionVolume 7 section 3 Part 1 HD 28/151 The purpose of this document is to describe how the provision of appropriate levels of skid resistance on the UK strategic road network will be managed.

7 This document describes how measurements of skid resistance are to be made and interpreted and is complemented by HD36 (DMRB ), which sets out advice on surfacing material characteristics necessary to deliver the required skid resistance While this document is not intended for management of skid resistance on local roads, similar principles may be In this document, the term skid resistance refers to the frictional properties of the road surface in wet conditions. The skid resistance of a wet or damp road surface can be substantially lower than the same surface when dry, and is more dependent on the condition of the surfacing To achieve consistency, skid resistance is measured using a specified device, under standardised conditions.

8 These measurements are used to characterise the road surface and assess the need for maintenance , but cannot be related directly to the friction available to a road user making a particular manoeuvre at a particular Skid resistance surveys are sometimes carried out for special purposes, such as research or local investigations. Due to the different test procedures, these measurements require careful interpretation. The data from such surveys do not form part of this Standard. The objectives of this Standard are to:i. Maintain a consistent approach to the provision of skid resistance across the strategic road network, so that road users find consistent friction characteristics when accelerating, braking and Provide a level of skid resistance appropriate to the nature of the road environment at each location.

9 The appropriate level is determined from a combination of: network-wide analyses of crash history, consideration of friction demands by road users and local judgement of site-specific factors (by suitably experienced engineers). This Standard provides advice and guidance to assist the engineer in determining an appropriate level of skid resistance for each site. It lays down the procedure to be used for measuring the skid resistance and, for cases where the measured skid resistance is at or below a predetermined level, provides a methodology to assist the engineer in assessing the requirement and priority for remedial works. Remedial works will be subject to an economic assessment of the costs and benefits before proceeding, to promote the best use of maintenance In this Standard, the provision of appropriate levels of skid resistance is treated primarily as an asset management issue rather than one of road safety engineering, although the crash risk is assessed in order to determine an appropriate level of skid resistance for each site.

10 Specifically, this Standard does not address the identification of locations or routes where road safety engineering measures could be beneficial to reduce 2015 Chapter 1 IntroductionVolume 7 section 3 Part 1 HD 28 Chapter 2 summarises the operation of the skid resistance Standard. Chapters 3 to 7 describe key components of the Standard: the measurement of skid resistance, setting Investigatory Levels, initial investigation, detailed site investigation and prioritisation and use of slippery road warning These chapters are supported by a number of Annexes that give more detailed instructions or advice. Annex 1 provides background information relevant to the measurement and interpretation of skid resistance.