Roads, railways and waterways are the responsibility of the Finnish Transport Infrastructure Agency. The police supervise traffic and compliance with traffic regulations. Rail transport is the responsibility of the national rail transport operator VR Group. Bus transport is provided by private bus companies and sub-regional transport consortia. The administration of taxi licences has been centralised to four Centres for Economic Development, Transport and the Environment. The national air transport company Finavia is responsible for the airports and the safety of air traffic.