Car traffic volume continues to rise in the majority of countries for which data are available. One particularly notable exception is the USA where car traffic has declined by 4.9% since 2007 – equivalent to 130 billion fewer car-kilometres in 2012 than in 2007. The USA continues to be home to the world’s largest car parc with 129 million cars in use in 2012 and even two-thirds of the lowest earning 10% of households own a passenger car – the highest proportion outside of the Middle East.