APPENDIX F – DRAFT TRANSPORT SCOTLAND LEAFLET: SCOTTISH
ROADS AND LANDSLIDES
by M G Winter, F Macgregor and L Shackman
Landslides are a natural part of the group of processes by which
mountainous landscapes erode over the course of time.
F.1 PRECAUTIONS FOR SAFER JOURNEYS
It is important that a precautionary approach is followed when
travelling in the more mountainous areas of Scotland during periods
when landslides are likely. Landslides are most likely during and
immediately after periods of very heavy rainfall, especially if the
heavy rain follows an extended rainy period. Landslides are most
prevalent in the periods July to August and October to January.
Simple precautions that you can take to minimise the chances of
your journey being disrupted during periods when landslides are
more likely include the following:
- Avoid unnecessary journeys, particularly those during the hours
- If you must travel, allow extra time for your journey.
- Check the weather forecast prior to your journey.
- During your journey
- Take account of driver information messages on the road
- Take account of travel announcements on the radio.
- In very mountainous areas it is inadvisable to stop on bridges
or adjacent to water courses.
- Take frequent rest periods away from the road in safe stopping
areas such as towns and villages rather than immediately adjacent
to the road in open country.
- Provided that the weather and other conditions permit, it is
best to continue your journey than to stop on the open road for
- Be alert to the possibility of water or debris on the road and
be prepared to stop unexpectedly.
Scotland is renowned for some of the most spectacular mountain
landscapes in the World. Such natural beauty attracts visitors who
make use of the landscape for a variety of recreational purposes
The mountain landscape of Scotland is developing actively, as
are all such landscapes. The current period of activity began
around 10,000 years ago towards the end of the last ice advance and
retreat to affect the area north of Scotland. All of this means
that landslides happen fairly frequently in Scotland. Most occur
high on the hillsides and do not have any effect on
Scotland’s resident population, its visitors or its
However, occasionally, an episode of significant magnitude will
inevitably occur. Such an episode was experienced in August 2004
when rainfall substantially in excess of the norm fell in parts of
The rainfall was both intense and long lasting and a large
number of sudden and rapid landslides, in the form of debris flows,
were experienced in the hills of Scotland. A small number of these
affected the trunk road network, notably the A83 between Glen
Kinglas and to the north of Cairndow (9 August), the A9 to the
north of Dunkeld (11 August), and the A85 at Glen Ogle (18 August)
Figure F.1 – A86 Loch Laggan.
While major injuries were avoided in August 2004, some 57 people
were taken to safety by helicopter after being trapped between the
two debris flows on the A85 in Glen Ogle (Figure F.3). The A85 was
closed for four days and the events on the A83 and the A9 meant
that they were closed for two days. The disruption experienced by
local and tourist traffic, as well as to goods vehicles, was
Figure F.2 – A83 Cairndow.
Figure F.3 – A85 Glen Ogle.
F.3 TRANSPORT SCOTLAND ACTIONS
Following the events of August 2004, Transport Scotland
commissioned studies on debris flows and their management. Initial
results were published in Summer 2005 and an implementation report
in Autumn 2008 (available from www.transportscotland.gov.uk).
The initial study specifically dealt with the following
- Considering the options for undertaking a detailed review of
side slopes adjacent to the trunk road network and recommending a
course of action.
- Outlining possible mitigation measures and management
strategies that might be adopted.
- Undertaking an initial review to identify obvious areas that
have the greatest potential for similar events in the future.
The 2008 study includes a detailed review of the network to
identify the locations of greatest hazard, to rank those hazards
and to develop appropriate management and mitigation measures that
may be targeted at appropriate sites. A suite of management actions
is currently being implemented on the network.
The overall objective of these studies is to ensure that in the
future Transport Scotland has a system in place for assessing and
managing the hazards posed by debris flows. In addition, the system
will rank the hazards on the network in terms of their relative
potential effects on road users. Whilst it is acknowledged from the
outset that it is not possible to prevent the occurrence of such
events this system will ensure that the exposure of road users to
the consequences of future debris flow events is minimised.