Source IRTAD for the following data Number of vehicles: 2005 except Ireland 2003; Luxembourg 2004; Slovakia 2002. Length of the network: 2005 except Hungary and Luxembourg 2004; Germany and Denmark 2003; Slovakia 2002; Iceland 2000; Ireland 2001; Netherlands 1999; Greece and United Kingdom 1998; Portugal 1993; Italy 1992. Distance in Kilometres: 2005 except Denmark 2004; Italy and Netherlands 2003; Ireland 2001; Iceland and Slovakia 2000; United Kingdom and Greece 1998.