My Urban Car

How can we get the London ULEZ back on track?

The Mayor of London is a passionate campaigner against air pollution and yet his clean air strategy appears increasingly ineffective and open to cynicism and frankly..ridicule.

The congestion charge exemption for electric vehicles is the only incentive the London Mayor offers to encourage drivers to switch from polluting diesel vehicles to zero emission vehicles. If the exemption is removed then both diesels and EVs would pay the congestion charge but be exempt from the ULEZ.

If the Mayor removes the EV exemption and an EV pays the same as 10 year old polluting diesels to drive in London then the policy charges people money while providing zero encouragement to cut pollution.

He either needs to keep exempting EVs from congestion charge or stop exempting all diesels from the ULEZ pollution charge.

Otherwise the Mayor is valuing the societal cost of air pollution on health and the climate impact of CO2 emissions at zero. For someone who cares as much about both issues he needs to deliver a policy that reflects that.

How could the exemption for diesel or other combustion vehicles be removed?

Currently the London ULEZ along with several other UK CAZ’s or Clean Air Zones exempt diesel vehicles approved under the EU Euro 6 emission standard introduced from September 2015. It is likely that any change to this exemption would need consultation or approval from central government. These vehicles remain highly polluting even when compared to petrol combustion cars for reasons we outline in our article here. At the same time getting London clean air policy back in alignment with cutting air pollution and greenhouse gases from vehicles is politically challenging.

Option 1 – Remove all diesel exemptions

  • Policy – the ULEZ exemption removed on the 25th December 2025 for all diesel cars and vans
  • Controversy level – Very high
  • Effectiveness of policy – very high
  • Diesel owners affected – all diesels past or future
  • While relatively few car drivers in London would be affected, diesel remains the fuel of choice for van drivers and many are on 3 year leases. This would make a sudden policy change affecting existing vans difficult.
  • A variation on this is a staggered set of charges lower than the current ULEZ for all vehicles that are not fully electric.. lower rate for hybrids and petrol and higher for currently exempt diesel.

Option 2 – The diesel sunset

  • Policy – Each year the start date for the start date for exemption would move forward by 2 years
    eg Current exemption from Sept 2015
    Under diesel Sunset
    In year 1 this becomes 2017
    In year 2 this becomes 2019
    By year 5 only diesels sold since 2025 would be exempt*
  • Controversy level – medium as different owners are affected each year
  • Effectiveness – High but slower than option 1
  • Diesel owners affected – a small proportion each year
  • Diesel vehicles get more polluting as they get older and the diesel sunset would remove the ULEZ exemptions from the oldest vehicles first

Option 3 – Final diesel purchase date

  • Policy – any new or used diesel car or van purchased after the specified date would lose its ULEZ exemption.
  • Controversy level – very low as no one’s existing diesel would be affected and anyone paying the charge would have chosen to buy a diesel knowing it was not exempt.
  • Effectiveness – high but only over the very long term and only if used vehicle purchases also lose exemption as it soon as it transfers to a different owner. Essentially every new or used diesel car or van transaction reduces the number of exempt vehicles.
  • Existing owners affected – none

Option 4 – Diesel van ULEZ charge and grant combination

  • Policy – All diesel vans lose exemption but van owners can recover 90% of any ULEZ payments over a 12 month period if they use it to buy or lease an electric van and sell or scrap the diesel. Only available on a single vehicle once.
  • Controversy level medium
  • Effectiveness high – diesel vans are highly polluting
  • Diesel owners affected – Applies to all vans and pickup trucks but not cars
  • Further background – this would replace much of the current dysfunctional grant program which pays owners to scrap one diesel van in order to put another diesel van back on the road.

Option 6 – diesel sunset and final diesel purchase date combined

  • Policy – after the final purchase date no new or used diesel purchased would have an exemption while at the same time each year another 2 registration years of the oldest most polluting diesels lose their exemption
  • Controversy level – still medium
  • Diesel owners affected – considering all are eventually affected controversy level could be surprisingly low for achieving a diesel free city.


The London ULEZ made a good start at cutting air pollution and has expanded to a vast area. Its weak point, the exemption of many extremely polluting vehicles it becoming a critical issue. Action is now needed if any further progress is sought. Option 6 would be our preferred option in terms of high effectiveness and with lower controversy.

David Nicholson

David Nicholson Is the founder of Rivergecko Ltd & MyUrbanCar which provide consultancy and advice for drivers and fleets to speed the transition from dirty fossil fuel transport to clean vehicles powered by renewable energy on land water and air.

The @MyUrbanCar twitter feed is a source of news & reviews of electric & plugin cars and vans in the UK.
The @rivergecko twitter feed & websites bring news and opinion on cleantech transport including cars, vans, buses, trucks, shipping, rail & aviation as well as autonomous vehicles & renewable energy, air pollution & motor industry news.

David Nicholson has worked as an underwriter at Lloyd's of London since the 1980's. His interest in technology goes back many years including interactive mapping, apps, green tech, boats, solar and cars.