The merits of separating cars and lorries have long been debated. Potential advantages include smoother traffic flows, lower accident rates, improved air quality and reduced maintenance and road infrastructure costs. Larger lorries are often banned from urban roads and restricted to certain lanes on many highways but there are no dedicated lorry facilities. However lorry-only lanes and lorry toll roads are now being actively studied. Tollson cars and lorries are also becoming increasingly common and could be used to distribute car and lorry traffic over road networks more efficiently. This paper reviews the potential benefits from separating cars and lorries onto different lanes or roads while treating road infrastructure as given. Studies in the USA of mixed traffic operations, lane restrictions and differential speed limits do not provide consistent evidence on whether separating cars and lorries either facilitates traffic flows or reduces accident rates. Analysis with an economic model reveals that the potential benefits depend on the relative volumes of cars and lorries, capacity indivisibilities and the impedance and safety hazard that each vehicle type imposes. Differentiated tolls can support efficient allocations of cars and lorries between lanes. Lane access restrictions are much more limited in effectiveness. Toll lanes that are dedicated to either cars or lorries are a potentially attractive hybrid policy. Intelligent transport systems (ITS) technology can help to improve safety and journey time reliability, and help drivers select between tolled and untolled routes. For the covering abstract see ITRD E146823
Abstract