Pavement deflection characteristics are related to performance under traffic, and deflection-criterion curves are given for roads with crusher-run bases and bitumen-macadam surfacings in the Malaysian environment. It was found that typical Malaysian bituminous overlays reduced deflections less than might be expected from experience gained elsewhere. In spite of the high rainfall in the country and the permeable pavement construction employed, it was found that subgrade moisture contents are rarely more than 2 per cent wetter than the optimum moisture content in the British Standard 2.5 kg rammer compaction test and they are usually significantly drier than this. It is concluded that the pavement design recommendations for flexible pavements in environments similar to that of Malaysia, and that the use of sub-bases in Malaysia would be advantageous