This paper introduces a new methodology based on risk analysis for the sele
ction of the best route for the transport of a hazardous substance. In orde
r to perform this optimisation, the network is considered as a graph compos
ed by nodes and arcs; each are is assigned a cost per unit vehicle travelli
ng on it and a vehicle capacity. After short discussion about risk measures
suitable for linear risk sources, the are capacities are introduced by com
parison between the societal and individual risk measures of each are with
hazardous materials transportation risk criteria; then are costs are define
d in order to take into account both transportation out-of-pocket expenses
and risk-related costs. The optimisation problem can thus be formulated as
a 'minimum cost now problem', which consists of determining for a specific
hazardous substance the cheapest flow distribution, honouring the are capac
ities. from the origin nodes to the destination nodes. The main features of
the optimisation procedure, implemented on the computer code OPTIPATH, are
presented. Test results about shipments of ammonia are discussed and final
ly further research developments are proposed. (C) 2000 Elsevier Science B.
V. All rights reserved.