It was found that the mean percentage of road signs recorded by five subjects over the course of a 105 miles long car journey under optimal conditions was of the order of 90 per cent of signs passed. It was found that the mean percentage of drivers recording a road sign was 47 per cent of those passed it. (This figure is based on percentages obtained for five different road signs, the number of drivers involved being about 1000.). On analysing the data for these five signs, it was found that there was a significant difference between the percentage of drivers recording each one. This difference was postulated as being due to the degree of urgency of the information contained in each sign (as based on past experience), i.e. the more urgent the information, the higher the percentage of drivers recording the sign.