The growth of the RORO fleet is related to the growth in the global trade of vehicles, particularly cars. Conventionally, the car industry was characterized by regional production clusters servicing national markets, with most vehicles shipped by land transportation (road and rail). There was an export market, but it was of limited size since car consumption in developing economies was limited. Ships around 3,000 CEUs were adequate to service such a demand level.
The massive entry of Japan in the 1980s as a car exporter led to a push to increase RORO ship sizes in the range of 5,000 CEUs. Then, in the 1990s and 2000s, Korean and European car manufacturers expanded into global markets as RORO ships reached 8,000 CEUs. Electric vehicle exports from major Chinese manufacturers mainly push the latest wave of RORO ships above 9,000 CEUs.