Traffic separation was first introduced on a voluntary basis in the Dover Strait in September 1967, just over fifteen years ago. Compliance with the IMO provisions relating to traffic separation schemes has been mandatory for all ships during the last five years and for some ships for as much as ten years. It may therefore be appropriate to assess the effectiveness of routing off North West Europe by comparing collision statistics for five-year periods since 1957.

The results given in the following tables apply only to collisions involving trading vessels of over 100 g.r.t. under way and not engaged in any special activities. Collisions in harbours, rivers and congested port approaches where special circumstances apply are not included. The figures quoted for the Dover Strait have been checked against the results obtained by the National Maritime Institute but are based on different criteria, and there may be some discrepancies.

The area covered is the coastal region from the south-western approaches to the Ushant TSS to the approaches to the Elbe including all parts of the English Channel and the Dover Strait, but not including waters off the East Coast of England which are well clear of the traffic separation schemes and deep-water routes.

The numbers of collisions are based almost entirely on Lloyd's Weekly Casualty Reports. Information relating to encounter situations is based on voyage data supplemented wherever possible by information received from additional sources relating to the actual courses steered by each vessel. It is not claimed that the figures constitute a precise record but they should provide a good indication of changes in the incidence of collision off North West Europe.