The Editors of this report would like to acknowledge the inputs to this study by groups and individuals as described below.

Members of the original Working Group who are not specifically named as authors herein include S Martin (Halcrow), P McMillan (W A Fairhurst and Partners), A Sloan (Donaldson Associates) and M Willis (Arup) and are greatly thanked for their input to the study.

The SCOTS (Society of Chief Officers of Transportation in Scotland) Consultation Group included A Dean (South Lanarkshire Council), P Haslam (Moray Council), I Mackinnon (Perth & Kinross Council) and D Spence (Highland Council). This group provided valuable and greatly appreciated input.

A wide variety of colleagues, friends and collaborators from both the UK and overseas have, wittingly and (in some cases) unwittingly, contributed to the development of the work reported herein. Their contributions range from supplying information and data through discussions held in a variety of formal and informal fora on a wide variety of relevant subjects to, in some cases, a few simple words of encouragement. Such contributions include R Ahmad (University of The West Indies, Jamaica), Professor E Bromhead (Kingston University), Dr R Creighton (Geological Survey, Ireland), Professor M Culshaw (University of Birmingham), Professor M Davies (University of Auckland, New Zealand), Dr T Dijkstra and Professor N Dixon (both Loughborough University), Dr P Flentje (University of Wollongong, Australia), Dr T Glade (University of Vienna, Austria), Dr P Gori (USGS, USA), Dr A Hatheway (Consultant, USA), Dr L Highland (USGS, USA), Dr K Ho (GEO, Hong Kong SAR), Dr P Jennings (AGEC, Ireland), Professor S Lacasse (NGI, Norway), Dr P Lyttle (USGS, USA), Professor P Marinos (National Technical University of Athens, Greece), Professor D Petley (University of Durham), Professor L Picarelli (Second University of Naples, Italy), Dr G Pinches (Connell Wagner, New Zealand), Dr W Schultz (USGS, USA), T Smith (Westrek Geotechnical Services, Canada), K Turner (Ministry of Forests, BC, Canada), Professor P Versace (University of Calabria, Italy), Dr J Wasowski (National Research Council, Italy) and R Williammee (Texas Department of Transportation, USA). Many others have made more indirect contributions by variously sowing the seeds of thoughts and ideas. We would like to thank both those named above and those that remain unnamed. However, their mention does not imply endorsement of the work presented here.

A large number of Transport Scotland staff, too many to mention individually, have contributed to internal fora in which we tested our ideas against their broader objectives. However, we would like to acknowledge unstinting support and encouragement that we have received from J Barton (Chief Road Engineer) and his predecessor, J Howison OBE.

The Authors of Section 4 would additionally like to thank all those involved in the production of the data used in Section 4 of this report: M Garcia-Bajo, R Lawley, C Forster, D Boon and R Armstrong (BGS); all those involved in the generation of extra superficial geology coverage in Scotland (C Auton, N Golledge, T Bradwell and J Everest of the BGS); and those involved from the BGS Cartography Office at Murchison House. In addition, external members of the working group for the Section 4 work – comprising F Macgregor (Consultant to Transport Scotland), S Martin (Halcrow), I M Nettleton (Coffey Geotechnics), L Shackman (Transport Scotland), D Spence (Highland Council) and Dr M G Winter (Transport Research Laboratory) – contributed enormously in terms of experience and local knowledge to the development of the methodology, the production of the data and the associated results.

The work presented in Section 4, including the data and results described, were produced by BGS under contract to the Transport Research Laboratory, acting on behalf of Transport Scotland.

The site specific assessments, the results of which are reported in Appendix C, were carried out by Scotland TranServ under the supervision of Douglas Cumming and Dave Cheer. The surveys were carried out by Nicky Horsburgh, Peter Egan, Brendan Flynn and Christopher Boler.

Transport Scotland, Scottish Executive and its successor organisations retain full usage rights of the outputs and contracted deliverables from the GIS-based assessment reported in Section 4. Such usage is by its own staff and by its agents employed in the operating, maintaining and constructing the road network. In addition, hazard maps in electronic form have been supplied to relevant local authorities. The output forms part of a wider assessment of the hazards (and associated exposure and hazard rankings) posed to the Scottish road network and it users by debris flow type landslides. It is intended for use in the operation, maintenance and construction of the network. It is neither intended nor suitable for, and should not be put to, any other use.