When I read the description of road-bowling I realised it is virtually identical to 'Boßeln' played traditionally in a tiny part of the very North-West of Germany and the very North-East of the Netherlands (neighbouring regions). I went to their homepage and found out that they have European championships every four years in the three disciplines:
Irish iron bowl
Frisian wood bowl and
Dutch bowl
The championships are exclusively in Germany or Holland or Ireland. I guess it would be formally correct to call the three countries event (with a rare Italian team) a world championship.

Wolfgang