Evening Standard reporter Ross Lydall penned this article on 4th April:

Row erupts over black cab exemption to planned ultra low emission zone

“Londoners will, however, be astounded that the Mayor has exempted black cabs from measures which apply to everyone else. This is particularly surprising since Transport for London’s own figures show black taxis are responsible for 18 per cent of road transport nitrogen oxide emissions in central London.

Where does the highlighted statistic come from and is it accurate?

  • Title (pollution) doesn't match the claim ("nitrogen oxide emissions" specifically)
    – user5341
    Apr 7, 2017 at 15:35
  • All of London’s famous black cabs run on diesel and Diesel vehicles emit close to 40% of the capital’s emissions of both NOx and the particulate PM10 according to energydesk.greenpeace.org/2016/11/03/…. This references ippr.org/publications/… but I don't have time now to follow up if this leads somewhere.
    – user22865
    Apr 7, 2017 at 15:40
  • @user5341 changed it. Giving up my search for more info. #fakenews
    – asthmatic
    Apr 7, 2017 at 15:41
  • 1
    I misread the title when I first saw it and for one brief moment thought it said "black cats" and this question seemed far stranger and more fascinating. :) Apr 9, 2017 at 15:15

1 Answer 1


I've found a TFL consultation document which is broadly in line with the figure 18% of road emissions in Central London.


In 2013, road transport was responsible for 51%, with taxis accounting for 15% of that.

The projection for 2020 is for road transport to fall to 22% of the total, with taxis being 27% of that.

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