File images of London's Ultra Low Emission Zone (ULEZ), as London greatly expands the area within which it charges drivers of older polluting cars to help clean up the city's air, despite objections from some that it is too costly. The move forces owners of more polluting vehicles such as diesel cars to pay £12.50 ($17.20) per day to drive in a far bigger portion of the capital -- between northern and southern orbital roads -- which is home to nearly four million residents. FILE IMAGES OF LONDON'S ULTRA LOW EMISSIONS ZONE