Many nations restrict the duration truck drivers may be in service before requiring compulsory resting periods. Drivers on overnight rest breaks may check into roadside motels or sleep aboard their trucks. It is possible for drivers' compulsory resting time to begin when the truck arrives at a ro-ro ferry terminal, allowing overnight ro-ro ferries to serve as mobile motels for drivers while also carrying their trucks. By the time the ro-ro ferry arrives at its destination, truck drivers are well rested, have a meal and resume their on-road duties.
There are locations around the world where a navigable waterway runs parallel to major motorways that undergo severe traffic congestion problems. In Ontario, Canada, the main east-west highway that connects between Detroit MI and Montreal QUE passes through chronic traffic congestion that occurs at Toronto. There may be scope for overnight ro-ro ferry service to serve as mobile motels that carry trucks around that congestion.
The Upper St. Lawrence
During winter, ferry services operate on a section of the Upper St. Lawrence River while some winter shipping actually continues on the Upper Great Lakes. The Port of Montreal operates during the cold northern winter months, serving ocean traffic while the navigation locks between Montreal and Lake Ontario remain closed for the winter. Ferries also cross the Lower St. River near and downriver of Montreal. Also during winter, ice booms are installed on the Upper St. Lawrence River downstream the Port of Ogdensburg NY to assure smooth water flow into the international power dam.
