Driving Theory Test Questions and Answers. Every motor vehicle driver shall drive the vehicle in conformity with any indication given by the Mandatory Signs. It is an offence not to obey these signs. Cautionary Signs are meant for cautioning the driver about the hazards lying ahead on the road. The driver should obey these signs for safety. Informatory Signs are erected on the road to provide information on direction, destination, roadside facilities, etc. to the road user.