See more information about this guidance

Statistical data set

Figure 2: Mean hours when NO2 pollution was moderate or higher for roadside sites, 1997 to 2024

Updated 26 June 2025
Download CSV 7.39 KB

Site type Year Number of sites Daily Air Quality Index Mean number of hours per site
Urban Traffic 1997 7 Moderate 4 14.85714286
Urban Traffic 1998 15 Moderate 4 13.4
Urban Traffic 1999 17 Moderate 4 9.588235294
Urban Traffic 2000 19 Moderate 4 7.842105263
Urban Traffic 2001 21 Moderate 4 5.142857143
Urban Traffic 2002 21 Moderate 4 2
Urban Traffic 2003 20 Moderate 4 25.4
Urban Traffic 2004 22 Moderate 4 24.95454545
Urban Traffic 2005 22 Moderate 4 38.04545455
Urban Traffic 2006 21 Moderate 4 34.76190476
Urban Traffic 2007 18 Moderate 4 34.38888889
Urban Traffic 2008 24 Moderate 4 38.20833333
Urban Traffic 2009 27 Moderate 4 20.96296296
Urban Traffic 2010 30 Moderate 4 25.7
Urban Traffic 2011 31 Moderate 4 12.61290323
Urban Traffic 2012 29 Moderate 4 9.103448276
Urban Traffic 2013 32 Moderate 4 4.65625
Urban Traffic 2014 28 Moderate 4 3.928571429
Urban Traffic 2015 38 Moderate 4 4.868421053
Urban Traffic 2016 50 Moderate 4 5.22
Urban Traffic 2017 61 Moderate 4 2.786885246
Urban Traffic 2018 63 Moderate 4 1.444444444
Urban Traffic 2019 66 Moderate 4 0.772727273
Urban Traffic 2020 65 Moderate 4 0.138461538
Urban Traffic 2021 62 Moderate 4 0.080645161
Urban Traffic 2022 65 Moderate 4 0.046153846
Urban Traffic 2023 61 Moderate 4 0.016393443
Urban Traffic 2024 64 Moderate 4 0.0625
Urban Traffic 1997 7 Moderate 5 2.571428571
Urban Traffic 1998 15 Moderate 5 0.666666667
Urban Traffic 1999 17 Moderate 5 0.470588235
Urban Traffic 2000 19 Moderate 5 0.263157895
Urban Traffic 2001 21 Moderate 5 1.047619048
Urban Traffic 2002 21 Moderate 5 0.80952381
Urban Traffic 2003 20 Moderate 5 2.55
Urban Traffic 2004 22 Moderate 5 1.409090909
Urban Traffic 2005 22 Moderate 5 5.090909091
Urban Traffic 2006 21 Moderate 5 3.047619048
Urban Traffic 2007 18 Moderate 5 3.555555556
Urban Traffic 2008 24 Moderate 5 3.791666667
Urban Traffic 2009 27 Moderate 5 0.481481481
Urban Traffic 2010 30 Moderate 5 1.766666667
Urban Traffic 2011 31 Moderate 5 0.387096774
Urban Traffic 2012 29 Moderate 5 0.103448276
Urban Traffic 2013 32 Moderate 5 0.21875
Urban Traffic 2014 28 Moderate 5 0.142857143
Urban Traffic 2015 38 Moderate 5 0.289473684
Urban Traffic 2016 50 Moderate 5 0.52
Urban Traffic 2017 61 Moderate 5 0.475409836
Urban Traffic 2018 63 Moderate 5 0.047619048
Urban Traffic 2019 66 Moderate 5 0
Urban Traffic 2020 65 Moderate 5 0.030769231
Urban Traffic 2021 62 Moderate 5 0
Urban Traffic 2022 65 Moderate 5 0
Urban Traffic 2023 61 Moderate 5 0
Urban Traffic 2024 64 Moderate 5 0.046875
Urban Traffic 1997 7 Moderate 6 0.571428571
Urban Traffic 1998 15 Moderate 6 0.066666667
Urban Traffic 1999 17 Moderate 6 0.058823529
Urban Traffic 2000 19 Moderate 6 0.105263158
Urban Traffic 2001 21 Moderate 6 0.238095238
Urban Traffic 2002 21 Moderate 6 0.047619048
Urban Traffic 2003 20 Moderate 6 0.15
Urban Traffic 2004 22 Moderate 6 0.136363636
Urban Traffic 2005 22 Moderate 6 0.363636364
Urban Traffic 2006 21 Moderate 6 0.142857143
Urban Traffic 2007 18 Moderate 6 0.277777778
Urban Traffic 2008 24 Moderate 6 0.458333333
Urban Traffic 2009 27 Moderate 6 0.037037037
Urban Traffic 2010 30 Moderate 6 0.2
Urban Traffic 2011 31 Moderate 6 0.032258065
Urban Traffic 2012 29 Moderate 6 0
Urban Traffic 2013 32 Moderate 6 0.09375
Urban Traffic 2014 28 Moderate 6 0
Urban Traffic 2015 38 Moderate 6 0.026315789
Urban Traffic 2016 50 Moderate 6 0.08
Urban Traffic 2017 61 Moderate 6 0.06557377
Urban Traffic 2018 63 Moderate 6 0.015873016
Urban Traffic 2019 66 Moderate 6 0
Urban Traffic 2020 65 Moderate 6 0
Urban Traffic 2021 62 Moderate 6 0
Urban Traffic 2022 65 Moderate 6 0
Urban Traffic 2023 61 Moderate 6 0
Urban Traffic 2024 64 Moderate 6 0.015625
Urban Traffic 1997 7 High 7 0.142857143
Urban Traffic 1998 15 High 7 0
Urban Traffic 1999 17 High 7 0
Urban Traffic 2000 19 High 7 0
Urban Traffic 2001 21 High 7 0.047619048
Urban Traffic 2002 21 High 7 0
Urban Traffic 2003 20 High 7 0.05
Urban Traffic 2004 22 High 7 0.045454545
Urban Traffic 2005 22 High 7 0.045454545
Urban Traffic 2006 21 High 7 0.047619048
Urban Traffic 2007 18 High 7 0
Urban Traffic 2008 24 High 7 0
Urban Traffic 2009 27 High 7 0
Urban Traffic 2010 30 High 7 0
Urban Traffic 2011 31 High 7 0
Urban Traffic 2012 29 High 7 0
Urban Traffic 2013 32 High 7 0
Urban Traffic 2014 28 High 7 0.035714286
Urban Traffic 2015 38 High 7 0
Urban Traffic 2016 50 High 7 0
Urban Traffic 2017 61 High 7 0
Urban Traffic 2018 63 High 7 0
Urban Traffic 2019 66 High 7 0
Urban Traffic 2020 65 High 7 0
Urban Traffic 2021 62 High 7 0
Urban Traffic 2022 65 High 7 0
Urban Traffic 2023 61 High 7 0
Urban Traffic 2024 64 High 7 0
Urban Traffic 1997 7 High 8 0
Urban Traffic 1998 15 High 8 0
Urban Traffic 1999 17 High 8 0
Urban Traffic 2000 19 High 8 0
Urban Traffic 2001 21 High 8 0
Urban Traffic 2002 21 High 8 0
Urban Traffic 2003 20 High 8 0.05
Urban Traffic 2004 22 High 8 0
Urban Traffic 2005 22 High 8 0.045454545
Urban Traffic 2006 21 High 8 0
Urban Traffic 2007 18 High 8 0
Urban Traffic 2008 24 High 8 0
Urban Traffic 2009 27 High 8 0
Urban Traffic 2010 30 High 8 0
Urban Traffic 2011 31 High 8 0
Urban Traffic 2012 29 High 8 0
Urban Traffic 2013 32 High 8 0
Urban Traffic 2014 28 High 8 0
Urban Traffic 2015 38 High 8 0
Urban Traffic 2016 50 High 8 0
Urban Traffic 2017 61 High 8 0
Urban Traffic 2018 63 High 8 0
Urban Traffic 2019 66 High 8 0
Urban Traffic 2020 65 High 8 0
Urban Traffic 2021 62 High 8 0
Urban Traffic 2022 65 High 8 0
Urban Traffic 2023 61 High 8 0
Urban Traffic 2024 64 High 8 0
Urban Traffic 1997 7 High 9 0
Urban Traffic 1998 15 High 9 0
Urban Traffic 1999 17 High 9 0
Urban Traffic 2000 19 High 9 0
Urban Traffic 2001 21 High 9 0
Urban Traffic 2002 21 High 9 0
Urban Traffic 2003 20 High 9 0
Urban Traffic 2004 22 High 9 0
Urban Traffic 2005 22 High 9 0
Urban Traffic 2006 21 High 9 0
Urban Traffic 2007 18 High 9 0
Urban Traffic 2008 24 High 9 0
Urban Traffic 2009 27 High 9 0
Urban Traffic 2010 30 High 9 0
Urban Traffic 2011 31 High 9 0
Urban Traffic 2012 29 High 9 0
Urban Traffic 2013 32 High 9 0
Urban Traffic 2014 28 High 9 0
Urban Traffic 2015 38 High 9 0
Urban Traffic 2016 50 High 9 0
Urban Traffic 2017 61 High 9 0
Urban Traffic 2018 63 High 9 0
Urban Traffic 2019 66 High 9 0
Urban Traffic 2020 65 High 9 0
Urban Traffic 2021 62 High 9 0
Urban Traffic 2022 65 High 9 0
Urban Traffic 2023 61 High 9 0
Urban Traffic 2024 64 High 9 0
Urban Traffic 1997 7 Very High 10 0
Urban Traffic 1998 15 Very High 10 0
Urban Traffic 1999 17 Very High 10 0
Urban Traffic 2000 19 Very High 10 0
Urban Traffic 2001 21 Very High 10 0
Urban Traffic 2002 21 Very High 10 0
Urban Traffic 2003 20 Very High 10 0
Urban Traffic 2004 22 Very High 10 0
Urban Traffic 2005 22 Very High 10 0
Urban Traffic 2006 21 Very High 10 0
Urban Traffic 2007 18 Very High 10 0
Urban Traffic 2008 24 Very High 10 0
Urban Traffic 2009 27 Very High 10 0
Urban Traffic 2010 30 Very High 10 0
Urban Traffic 2011 31 Very High 10 0
Urban Traffic 2012 29 Very High 10 0
Urban Traffic 2013 32 Very High 10 0
Urban Traffic 2014 28 Very High 10 0
Urban Traffic 2015 38 Very High 10 0
Urban Traffic 2016 50 Very High 10 0
Urban Traffic 2017 61 Very High 10 0
Urban Traffic 2018 63 Very High 10 0
Urban Traffic 2019 66 Very High 10 0
Urban Traffic 2020 65 Very High 10 0
Urban Traffic 2021 62 Very High 10 0
Urban Traffic 2022 65 Very High 10 0
Urban Traffic 2023 61 Very High 10 0
Urban Traffic 2024 64 Very High 10 0