This is the fifteenth annual report of the International Road Federation's continuing World survey of current Research and Development on Roads and Road Transport. It covers a total of 54 countries, including the United States. Since 1965 the series has reported on the activities in 77 countries, having included a cumulative total of 72,414 entries, corresponding to some 33,000 individual projects. Thirty-five in-depth studies on selected technical subjects have also been completed under the program. It represents the only world-wide inventory of highway research in progress, being a cooperative effort of the Federal Highway Administration and the International Road Federation. The purpose of the R & D report is to provide for all who may be interested in highway matters a simple, timely record and summary of current highway research and development throughout the World. The purpose is not only to compile and record the existing projects, but to encourage an interchange of information among researchers. The ultimate goal is to assist the countries in developing more productive highway research programs which will mean better and safer roads, lower maintenance costs and better living.