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Opportunity and choice criteria for automatic thawing agent spraying systems (VSS2001/602)

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Complete with results
Geo-spatial type
Project website
STRIA Roadmaps
Infrastructure (INF)
Transport mode
Road icon
Transport policies
Environmental/Emissions aspects
Transport sectors
Passenger transport,
Freight transport


Background & Policy context

Maintenance of the road network in acceptable use and safety conditions at all times or almost requires substantial means of intervention. Despite this, on various specific points of the road network (structures, highly loaded sections) winter maintenance remains problematic. From the standpoint of the safety of road users, IADs (automatic de-icing systems) can treat the floor at the appropriate time, that is to say just before the onset of the risk of loss of adhesion coating, which does not allow winter maintenance by conventional means. To reduce significantly the risk of loss of traction, the trucks by salting requires preventive applications. Now they are not recommended, see banned because of their impact on the environment. Using IAD s' is therefore not only wise for the safety of users, but also in economic terms, the guarantee of an optimal flow capacity for traffic, by reducing accident costs and a salting strictly limited to needs.


For about 25 years already, automatic thaw agent spraying systems have been a contribution to the task of winter maintenance. These systems allow a quick intervention as soon as a risk of
icing of the roadway appears by spraying a liquid thaw agent. The crucial research need is to supply an evaluation method that can justify the implementation of an automatic thaw agent
spraying system, considering all important aspects. 


The main goal of this research is to define the conditions justifying the installation of an automatic anti-icing system in a road section, taking into account climatic, topographic, geometric, ecological, economical and safety aspects.

The study will present an evaluation method to road owners (FEDRO and regional road authorities), which allows to determine whether or not the establishment of an automatic anti-icing system is justified. This method will be adapted to the amount and quality of data available for the project.


Parent Programmes
Institution Type
Public institution
Institution Name
Swiss Government: State Secretariat for Education and Research
Type of funding
Public (national/regional/local)



Automatic thaw agent spraying systems are an efficient tool for the task of winter maintenance. The possibility of intervening almost instantly whenever an icing risk appears raises considerably the winter service level and road safety. Nevertheless, the still quite high installation and operation cost of these systems call for a preceding evaluation by the authorities in order to justify the investment.

Once the two steps of the suggested evaluation method carried out, the decision to set up an automatic thawing agent spraying system can be taken being reassured that all important and necessary aspects have been analysed.

The examples treated during the research project show that the decisions taken until today were justified and the systems well adapted to their specific situation.

The suggested evaluation method is supposed to be independent from technical development and the cost evolution. The automatic thawing agent spraying systems evolve and their installation is getting more accessible: the construction is getting easier and the maintenance and operation cost decrease. The adopted method remains valid despite this development, as the most important criteria for the justification and the equipment choice don’t change.

Other results

A.-G. Dumont, D. Baumann (2005) Criteria for opportunity and choice of automatic de-icing facilities, VSS Report No XXXX, Zürich
D. Baumann, Dumont A.-G. (2004), Evaluation of the automatic de-icing facilities, Road and Traffic 11/2004, pp.15-18
D. Baumann, Dumont A.-G. (2005), Opportunity and choice criteria for automatic thawing agent spraying systems. Proceedings of the 5th Swiss Transport Research Conference Monte Verita.


Lead Organisation
EU Contribution
Partner Organisations
EU Contribution


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