MikeT wrote: ↑06 Jul 2017, 11:50According to Defra, in 2015 Private cars account for appx one third the roadside concentration of NOx pollutants in London. HGV's, LGV's, buses and taxis create the majority. This (appx 60%) is aside from the NOx pollutants that drift in the air from outlying sources.
ETA: Which by my approximation means private cars contribute about 18% NOx emissions in London.
https://consult.defra.gov.uk/airquality ... 20Plan.pdf
Interesting, I suppose it depends on how you measure it, (why only measure private cars and exclude commercial vehicles, most of which are Diesel ?) but the same report you linked also says:
So clearly there is a "hot spot" issue as I was saying earlier where the concentrations of NOx at the roadside are a lot higher than the average across the whole of London. And the roadside is where a lot of people spend a lot of their time, whether pedestrians or commuters.14.Although non-transport sources of NOx are considerable contributors (Figure 2) road
transport is responsible for some 80% of NOx concentrations at roadside, with diesel
vehicles the largest source in these local areas of greatest concern (Figures 3a; 3b and
11 This is due to both the significant growth in vehicle numbers, particularly diesel
vehicles, and improvements in real world testing showing that laboratory test-based
emission standards have not delivered expected reductions under real world driving
conditions (see also Section 6).