The category of accidents external costs embraces a broad range of different situations in industry, transport and civil activities.
Given that in industrial activities (mining, chemical processes, refining, etc.) safety is a target for the whole organization, external costs to society may arise in industrial or in professional accidents because of an insufficient consideration of safety within budget and organization. As it happens in environmental pollution risk, external costs of accidents are not connected with compliance to legislation: legislation may reduce industrial and professional health risks (and related external costs) but it can hardly assure a zero risk, so external costs may be generated even in full compliance with existing regulations.

In the transport sector, the main impact pathways of accidents are:
- Direct health impacts of transport accidents
- Impacts on vehicles and infrastructures
- Loss of time and other internal and external costs associated to congestion due to transport accidents (particularly important in case of accidents in tunnel)
- Environmental and health effects due to land accidents with release of dangerous substances
- Effects on marine and coastal habitats associated to the maritime transport accidents (release of dangerous substances at sea)

In the past years the accidents sector was considered a low uncertainty valuation area. Indeed the application of impact pathways approach to accidents highlighted the need for major innovation in valuation methods, in statistical monitoring, and even enlarged the range of policies. A more integrated approach is needed, that goes from basic prevention (education and control) to mitigation of undesired effects such as costs of congestion (traffic diversion). For example, in the field of statistics, this means that new data are needed: from Police time effectively dedicated to vehicles road regulation compliance, to data on vehicle responsibility in case of accidents and their harmfulness characteristics (weight). Because of lack of these data, in the present situation of statistics it may appear that a heavy good vehicle averagely generates less accident costs than a scooter! Another field of ongoing discussions is which cost categories fall onto society in case of an accident and which are already borne by the vehicle manager (which are the external costs component to consider). The “user club” perspective assumes that all risks are payed by the users, so external costs are zero. Unfortunately pedons and cyclist are citizens too and the user club seems to be a club of happies with hundreds of killings in un underground cellar!
Other perspectives assume more realistic approaches, recognising that vehicles managers/users are first of all citizens integrated in the network of social relationships (parents, relatives, friends, colleagues, famous persons, etc.), so that an accident has always a lot of different effects on this network and it’s very difficult to say that these effects are not outside of the transport user sphere. So the point of accident external costs calculation becomes to which extent the internal cost component (insurance premiums) succeeds in covering the high external costs of accidents.

© 2006 - Andrea Molocchi