Speed is an important contributor to road accidents and also affects driver speed behavior, the present study focuses on how effective traffic advisory information is when helping drivers to divert from potentially dangerous conditions. Graphical representation of an Expressway section made it easy to isolate the effects of speed etc. by drivers with information provided through VMS under adverse fog conditions. Understanding and reacting to the VMS system by drivers is essential for its success. If drivers do not react by changing speed behavior then the VMS system will fail and further implementation may cease. The result of this experiment is limited to the considered situation and VMS message on a simulated section of expressway and shows that provision of traffic advisory information through VMS can affect driver behaviour and speed. Countries that are planning to implement intelligent transport system, especially developing and under developed countries, to achieve reduction of road accidents should give thought to Variable Message Signs.