Abstract
Effects of two types of stop signs on driving behaviours of private car and commercial vehicle drivers were examined. the subjects were 1211 male and female nigerians whose driving behaviours were observed as they drove through a complex t-junction. trained observers recorded how far each driver conformed with the demands of standard traffic regulations. the results showed that (a) private car driversconformed more to traffic regulations than did drivers of commercial vehicles and (b) drivers who obey stop signs tended to make turn signals. installation of more traffic signs on nigerian roads and theeducation of the drivers (especially the commercial vehicle drivers) as to the specific demands of such traffic signs are advocated.(A)