In many parts of England, the main form of road
surface treatment necessary during the winter is the spreading of a
mixture of grit and salt. This always takes place on selected roads
when conditions are definitely icy. A difficult situation arises,
however, when the weather is at the borderline of icy conditions,
especially when meteorological forecasts state "temperature will be
below zero but surfaces are expected to remain dry."
Engineer Officers are closely involved in the salting
and gritting operations. The quality of the grit/salt mixture, its
effectiveness, its purchase and storage at suitable points, the vehicles
and equipment used, the roads selected, the routes followed, the speed
at which the work is done, etc., etc., generally come under the aegis of
the technical services or highways department, in which there is a
preponderance of engineers, including a number with identified
When a borderline meteorological forecast is
received, most authorities do not automatically call out the
gritting/salting teams for that may involve unnecessary expenditure and
an excess of corrosive salt on the roads, both of which result in
complaints by members of the public. Moreover in an unexpectedly harsh
winter there may be shortages of grit/salt mixture, not just locally but
nationally, or it may be difficult to move supplies from central stocks
because of the same wintry Conditions. It may therefore become
necessary to conserve whatever local stocks there are.
One aid to decision-making about borderline
conditions is to carry out local tests on parts of the road system
particularly prone to ice formation. How many test points should there
be and where should they be located? What tests should be carried out,
who should carry out the tests (which are often needed in: the middle of
the night), how should the results be collated and who should make the
final decision about gritting and salting on that particular occasion?
These are questions to which engineer Officers usually have to supply
the answers and Councillors, engineering or otherwise, have to approve
in broad outline.
For the vast majority of occasions the whole scheme
works well and achieves. a satisfactory balance between the many
conflicting requirements outlined. Occasionally, however, with the
system working as intended, a decision is taken not to treat the
surfaces but unexpected conditions occur which cause icy patches on the
roads. This has led to loss of life.