In Ireland there are eleven tolled road-transport schemes, operated by various independent operators. The majority of these are tolls on a major bridge or tunnel on the route. All tolled roads in the Republic were built under a public-private partnership system, giving the company which arranged for the road to be built the right to collect tolls for a defined period. Tolls vary from €1.65 to €12 for cars. Larger vehicles pay more, with the exception of the Dublin Port Tunnel, where buses and heavy goods vehicles travel toll-free.