Generalized Visibility of Freeway in Adverse Weather Conditions

In adverse weather conditions, safe operation on freeways is closely related to the "driver, vehicle and road" concept. In order to ensure a safe distance between vehicles on freeways, the traditional concept of visibility should be taken into account, as well as the physical state of the driver and vehicle performance, which overcomes the limitation caused by traffic control methods which are confined by the traditional view of visibility. By putting forward a new concept of generalized visibility (GV), along with a deep analysis of its calculation and application, this paper introduces the main achievement of a freeway management department by using the generalized visibility index (GVI), a comprehensive way that takes other factors (driver, vehicle and road) into consideration. Serving as a single composite index, GVI will be an important tool for traffic management departments to make a decision easily and for making traffic control more scientific and rational.