Electric cars are seen as a key way for the UK to meet its carbon budgets and cut the illegal levels of nitrogen dioxide pollution that blight many British cities. The number of 100% electric cars registered in the UK in 2015 nearly doubled on the year before, to 9,934. In Norway, incentives including generous tax breaks and allowing electric cars in bus lanes have spurred the introduction of the cars which now account for nearly one in five of all new cars sold.