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Inter-Vehicle Hazard Warning

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Complete with results
Geo-spatial type
Network corridors
Project Acronym
STRIA Roadmaps
Transport mode
Road icon
Transport policies
Societal/Economic issues,
Transport sectors
Passenger transport,
Freight transport


Background & Policy context

Many accidents are due to the difficulty drivers have in anticipating a dangerous point on the road. Therefore inappropriate driver behaviour, poor visibility or temporary loss of visibility due to obstacles or bad weather conditions can generate pile-up accidents. These are statistically not very frequent but often very serious, and could be avoided if a warning message had been delivered in time.


The main objective of this project was to develop a common and interoperable concept of inter-vehicle hazard warning to reduce risks of accidents, to measure its effects and identify possible conditions of commercialisation.


The main steps of the project were:

  • Content of messages and radio communication (size, contents, characteristics, speed, European coverage, etc); 
  • Integration within vehicles (optimisation of radio communication); 
  • Efficiency of alert messages: development of a model of driver's reaction; 
  • Safety issues: statistical analysis: which accidents can be avoided; 
  • Integration of markets: market study, comparison with the introduction of new technologies in the automotive sector (airbag); 
  • Technical and functional validation of the concept; 
  • Impact of the system on safety: study of drivers facing a dangerous situation, why and when a driver can send an alert message; 
  • Demonstration of the interoperability of the systems developed by each partner of the project.


Parent Programmes
Institution Type
Public institution
Institution Name
Ministère de l'équipement, des transports, du logement, du tourisme et de la mer (French Ministry of Transport), BMBF - Bundesministerium für Bildung und Forschung (German Federal Ministry of Education and Research)


An Inter-Vehicle Hazard Warning (IVHW) system was developed and demonstrated. This provides an in-vehicle warning in the event of an accident or incident ahead.

It was estimated which types and categories of accidents could avoided (or the follow-on effects of which could be alleviated) as a result of implementing the IVHW system. The relevant categories that have been defined are rear-end accidents, pile-ups after rear-end accidents and other complex accidents involving more than two vehicles where the initial accident was not a rear-end accident. Only injury-producing accidents occurring on motorways and rural roads have been taken into consideration.

The same classification has been used for the French and German accident database.

Taking into consideration ratios obtained from the in-depth accident analysis carried out by INRETS on a 1/50 sample of 1995-1996 accidents and different assumptions concerning the penetration rate of the system, an estimate of the potential savings has been made. The system could save 100 to 300 lives in both countries, depending on the number of vehicles which could be fitted with the IVHW equipment.
Clearly, the effectiveness of IVHW relies on the drivers' capacity to correctly activate the system in hazardous situations. The results are highly dependent on the vehicle equipment rate.

Policy implications

The introduction of IVHW cannot be compared with currently existing telematic services, for example emergency call via mobile phone or traffic information systems. Those services lack acceptance due to fees and additional costs when using the services. On the other hand, the IVHW system involves a terminal unit that is only useful if a certain proportion of vehicles on the road are equipped. Thus, there is a transition period in which IVHW units need to be built into the vehicles but the customer will not perceive any benefit and in which he, consequently, will not be willing to pay for an IVHW unit. The way to overcome this start-up problem could be to provide specific incentives to the end user (e.g. tax reduction).

To reach European market penetration quickly, major car manufacturers need to fit IVHW systems into their vehicles and preferably also road and motorway operators should install roadside warning beacons interoperable with the IVHW in-car equipment.


Lead Organisation
EU Contribution
Partner Organisations
EU Contribution


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