Five of these instruments address in particular pan-European land transport networks and services : ( a ) European Agreement on Main International Traffic Arteries ( AGR ) of 1975 ( 37 Contracting Parties ) ( b ) European Agreement on Main International Railway Lines ( AGC ) of 1986 ( 28 Contracting Parties ( c ) European Agreement on Main Inland Waterways of International Importance ( AGN ) of 1996 ( 13 Contracting Parties )