My Urban Car

Could a ULEZ diesel sunset deliver better London air quality AND fiscal balance?

In October we discussed how a government demand on expanding the London congestion charge could have been made to work. In the end the Government stepped back from insisting on this and gave TFL another short term grant but crucially, left the Mayor with the headache of working out how to increase revenue by January 2021. Having rejected adding the congestion charge to the enlarged ULEZ zone, the Mayor is left with looking for other funding options, including adding to his share of council tax.

His first policy idea has appeared since our proposal. We have compared it on what we believe are the key requirements against our diesel sunset proposal.

While initially seen as a victory for the Mayor, the government has arguably taken the heat of themselves and persuaded the Mayor to “in political not literal terms”, construct a scaffold and hang himself just before the Mayoral election. Indeed the first proposal submitted of a £3.50 a day toll to enter London may do exactly that by providing something that all drivers may oppose if given the right encouragement.

From a clean air perspective it is vital Sadiq Khan remains in office and delivers the air quality improvements of the expanded ULEZ as the London Conservative candidate for Mayor is firmly against taking action to reduce pollution from traffic. Far more so in fact than the Conservative party nationally or in other parts of the UK.

How a toxic diesel “sunset” could help

There were always 2 problems problem with the existing criteria for the London ULEZ called Euro 6 emissions standard.

  1. The ULEZ imposes a daily levy on driving diesel vehicles before the Euro 6 emissions standard (most diesels sold before Sept 2015) but exempts the Euro 6 diesels sold since then. This would make sense if these vehicles were much cleaner than previous diesels but they weren’t. Euro 6 diesels still produced NOx pollution well in excess of legal limits on the road and many still do although those sold since September 2019 are closer to legal limits set in 2015. The next Euro 7 standard which might be much tighter isn’t set to arrive till the mid 2020s.
  2. by choosing a fixed date, the arrival of the Euro 6 emissions standard which was introduced in Sept 2015 as the arbiter of whether a diesel vehicle pays the ULEZ (and a much earlier date for petrol cars) the proportion of cars charged falls annually! So each year a higher proportion of cars are ULEZ exempt and a smaller proportion pay it. By 2025 a 10 year old diesel will be exempt while in 2019 only diesels up to 4 years old were exempt.

Much of the benefit of the ULEZ didn’t just derive from diesels getting cleaner but simply because in 2019 the ULEZ was only exempting 4 and a bit years of newer diesel sales. If you assume the average UK diesel car has a life of 14 years then

  • in 2019 71% of diesel sales years had to pay the ULEZ while 29% were exempt. If no changes are made to ULEZ criteria this benefit to air quality goes into reverse and
  • In 2021 50% of diesels are ULEZ exempt rising to
  • 78% of diesels exempt by 2025 and
  • only 22% liable for the charge by 2030 when almost every diesel in the UK would be exempt!

Not only will you have 10 years worth of filthy exempt diesels but by then these cars will be older, less well maintained & probably with non functioning diesel particulate filters spewing out PM of all sizes.

In other words without changing the criteria diesel emissions are likely to plateau and then worsen sharply, limited only by falling new diesel car sales. Diesel share of new car sales declined from 50.1% in 2014 to 42% in 2017, then 31.7% in 2018 and 26.6% in 2019 (these include MHEV diesels). Diesel share in 2020 to November is at 20.1%. Diesel share is has currently plateaued at just under 1 in 5 sales, largely in the extra large luxury SUV segment. It’s also worth remembering that over 95% of van sales are still diesels and it is vital new vans switch to electric now the choice of models is finally good.

What is the diesel sunset?

The idea is a pretty simple one that brings better return on capital and increased revenue over time but also maintains improvements in air quality and then drives further improvement.

You keep the ULEZ Euro 6 diesel exemption but each calendar year from 2022 you remove the exemption from the oldest 2 years worth of the Euro 6 models. This means in 2021 you peak at 7 year old diesels being exempt. In 2022 the oldest 2015 and 2016 diesels lose exemption and by 2023 Euro 6 diesels sold in 2015, 2016, 2017, and 2018 will have lost exemption. By 2026 the only exempt diesels will exempt and in 2027 only 2027 diesels will be exempt

YearExempt Euro6 diesels
Proposed 2 year per calendar year sunset commencing 2021

Why this matters

  • It’s based on sound science. It is overwhelmingly clear from studies that earlier Euro 6 diesels were massively more polluting than petrol cars
  • While some newer diesels have improved even the latest RDE2 Euro 6 emissions standard still allows new diesels to produce far more NOx than petrol cars.
  • Even those diesels that pass RDE 1 or 2 on the road tests do so only when brand new and complex emissions control equipment is used and maintained perfectly. This equipment is expensive to maintain and replace and it is relatively easy for owners to circumvent expensive repairs allowing pollution to soar.
  • The sunset is not draconian, indeed it is not until 2024 that the number exempt diesel sales years is less than when the ULEZ was introduced. By January 2022, just after the expanded ULEZ zone starts it is only diesels more than 6 years old that would lose exemption
  • ”keep exemptions for 2015 and 16 diesel cars” hardly has the makings of a big campaign by motorists so it should be less politically toxic than a diesel exhaust.
  • The sunset restores the direction of travel to ULEZ policy and ends the rather ridiculous argument by some dieselmakers that Euro 6 diesels are no longer polluting because the Mayor says so by exempting them!
  • We have not discussed petrol cars which are currently all exempt on a 14 year life basis. Obviously even a 2 year annual sunset on the petrol exemption would take around 6 years before a 10 year old petrol car loses it’s exemption
  • The proposal also uses the existing infrastructure that is required for the ULEZ expansion in October 2021 and can there be rolled out at the same time
  • It’s worth bearing in mind that in 2025 the ULEZ criteria will reach a crescendo of absurdity. In only 4 years time under the Mayor’s plans Electric cars (EVs) will lose their London Congestion Charge exemption. At the same time 10 year old cars and vans will have become exempt from the ULEZ charge or ultra low emissions charge. So in a 2025 London traffic jam the 10 year old diesel or 20 year old petrol car spewing out fumes will pay the same to drive in London as a the zero tailpipe emission EV
  • This is an appalling prospect that removes any public policy purpose from the ULEZ unless a sunset is employed. The most obvious alternative way to deal with the ULEZ would be to do nothing till about 2023 then, once it is largely ineffective, shift the exemption date by 5 or more years in one go.. a “politically braver” move that would ignite opposition co-ordinated by the usual transport industry lobby groups.

Comparison with the alternative proposal being being considered by the Mayor of London for a £3.50 daily charge to enter a new zone of Greater London outside the ULEZ area.

Full details have not been published but based on what has been revealed so far…

This proposal was floated in December 2020 with this Guardian piece being the most friendly and has already produced a storm of protest in most of the newspapers. Here is how the proposal compares with our ULEZ sunset proposal.

Runs on expanded
ULEZ zone infrastructure
Can be implemented
by January 2022
Politically saleable to
most drivers
Reduces ULEZ revenue
Targeted to cut
exhaust pollution
higher revenue per charge
event & no new infrastructure
solves issue of more older
vehicles being ULEZ exempt
raising pollution & reducing
revenue each year
Congestion charge supplement
of £2.50 or £3.50 can be added
to outer ULEZ at any time

On the criteria we believe are important we don’t think a third zone with a £3.50 toll makes little sense, either to reduce pollution or congestion or to raise revenue

  • It is expensive and time consuming to implement
  • it is unclear the the boundary will be M25 which is the logical and simplest place for an outer zone boundary
  • If it is purely a toll on entering London (rather than being enforced on all vehicles travelling inside the zone) it would encourage traffic to travel within London rather than going round M25 and having to re-enter London
  • If it is set up to charge any cars travelling inside greater London then a vast new set of enforcement cameras would be needed but only raising £3.50 per vehicle per day. If you install than why not just expand the ULEZ to M25 boundary at the same time with the pollution and revenue benefits that would accrue.
  • We believe if a reduced rate “Congestion charge light” is to be introduced it should be applied first within the expanded ULEZ zone. The entire zone can then be expanded towards or to the M25 boundary over time.
  • It’s time the Mayor and TFL dealt with the ULEZ criteria flaw, continued to improve air quality and safeguard revenue and ensure policy encouraged sales of clean zero emission vehicles leading up to the 2030 ban.

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.