ULEZ becomes London-wide from today

The Ultra Low Emissions Zone (ULEZ) has expanded to become London-wide from today. As it expands, we look at the crucial role of measurements to determine the criteria for vehicles to meet ULEZ standards. Needless to say, they are all metric.

In February 2023, the Mayor of London published the Inner London Ultra Low Emission Zone – One Year Report. This report contains a number of findings, numbers of vehicles and compliance rates, fleet compositions, traffic impacts, emissions and air pollution concentrations.

Distances travelled by all vehicles are given exclusively in kilometres throughout the report. Monthly emissions rates for vehicles are expressed in grams per kilometre. The studies examine the quantities of nitrogen oxides (NOx), fine particulate matter (PM2.5), carbon dioxide (CO2) produced by vehicles. Aggregate quantities of these pollutants are expressed in tonnes. Concentrations of pollutants are expressed in micrograms per cubic metre (µgm-3).

The ULEZ emissions standards are based on the required Euro emissions standard for your vehicle and emission type. The ULEZ standards are 1:

  • Euro 3 for motorcycles, mopeds, motorised tricycles and quadricycles (L category)
  • Euro 4 (NOx) for petrol cars, vans, minibuses and other specialist vehicles
  • Euro 6 (NOx and PM) for diesel cars, vans and minibuses and other specialist vehicles

These different Euro emission standard categories define the maximum amounts of various pollutants that a vehicle can emit. These amounts are defined in grams per kilometre. 2 3 4

We use the metric system exclusively for ULEZ. These measurements are incompatible with the mile-based odometers in British vehicles, plans for pay-per-mile 5 6 and the almost exclusive use of imperial units on British road signs. There is also some use of dual units such as UK speedometers, restriction signs and fuel economy measures. What a mess!

Why are we using two measurement systems in the transport sector? Nobody in politics openly asks why we are using two competing and incompatible measurement systems unlike the rest of Europe including non-EU countries and most of the world. Sadly, we are stuck with it for the foreseeable until British politicians see sense and gain the courage to complete the UK’s transition to the metric system.

You can find more details about the ULEZ Expansion 2023 at:
https://tfl.gov.uk/modes/driving/ultra-low-emission-zone/ulez-expansion-2023

Sources:

  1. https://tfl.gov.uk/modes/driving/ultra-low-emission-zone/ways-to-meet-the-standard#on-this-page-0
  2. https://en.wikipedia.org/wiki/European_emission_standards
  3. https://www.theaa.com/driving-advice/fuels-environment/euro-emissions-standards
  4. https://www.rac.co.uk/drive/advice/emissions/euro-emissions-standards/
  5. https://www.bbc.co.uk/news/uk-england-london-60030127 (“London mayor wants daily driving charge of up to £2”, BBC News, 18 January 2022)
  6. https://www.driving.co.uk/news/roads/urgent-pay-per-mile-road-pricing-government/

One thought on “ULEZ becomes London-wide from today”

  1. I know that this item appeared some time ago now and I did not see fit at the time to comment on the unit usage itself, because Ronnie is absolutely right. However, I have been saddened to read in recent days how there has been community resistance to ULEZ primarily from people who apparently wish to continue to pollute our cities. Reducing these pollutants is imperative if we are to improve the health of especially young children who are otherwise forced to breathe in noxious substances. Often it is the poor children that suffer as they walk or cycle to school rather than be driven (ironically perhaps) by a parent.

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