As a preparation of a design standard regarding road facilities, such as cantilever columns for traffic lights, street lights on highways is proposed. Currently these minor structures are designed based on guidelines which are mixed with multiple old foreign specifications without any criteria in terms of safety and economy, which could lead irregular safeties and the loss of national properties. In the considered two cases for effective projected area, it is found that following efficient way of design without critical analyses could make significant errors and miscalculations. Therefore, a fundamental research on the minor structures is urgently needed.