The most important part of it is undoubtedly the recommendations made to member governments. These have been well thought out and ought to be adopted almost without exception. They are prefaced with a description of the aims which public policy ought to have, and in the context of traffic noise control, these aims refer to "seeking a realistic balance between the aspirations of the public and its willingness to pay." This concept of balance is an important one in the context of the competition which exists for the resources of all countries and it illustrates the reason why it is becoming more and more important to apply the techniques of cost benefit analysis to environmental considerations such as noise. There has in the past been a tendency to quieten those vehicles which inherently were easy to quieten and leave the more difficult cases to last. However, much of the annoyance caused by traffic noise is probably the result of the obtrusiveness of the louder vehicles in comparison with others and thus the policy should be to reduce the noise from the noisier heavy vehicles until it merges with that from saloon cars. At this stage the noise from all vehicles can be reduced simultaneously. In view of this it is encouraging that one of the specific proposals of the report is to give priority to the quietening of the noisiest vehicles. The report also recommends that governments should encourage the "development of alternative modes of transportation which produce less noise impact on the urban environment." This is a refreshing statement in a document dealing with traffic noise as quite frequently the aims of designers tend to become a little narrow. It is important to recognise that traffic is not the only means of transportation available in the urban environment. Reference is made in the document to the suggestion that Toronto has reached the limit of its capacity in relation to cars and that