Ferries typically perform short journeys for a mix of passengers, cars and commercial vehicles. Most of these ships are Ro-Ro (roll on – roll off) ferries, where vehicles can drive straight on and off, making it a speedy and easily accessible way to travel.
The capacity of ferries has expanded significantly in modern times to cater for more cars and heavy-freight vehicles. The ships often provide an economic and environmentally friendly alternative to other methods of transport. A special type of Ro-Ro ships is one designed just to carry new vehicles from where they were manufactured to their global customers, these are known as pure car and truck carriers (PCTC).
Many ro-ro vessels operate on short-sea trades and make frequent port calls. While shipping cargo is normally measured in metric tons, Ro-Ro cargo is measured in lane metres, which is calculated by multiplying the cargo length in metres by the number of decks and by its width in lanes.
Ferries and Ro-Ro ships may operate on a regular schedule and have less environmental impact than road-based alternatives.