Memo to Sadiq Khan: here’s how to redesign Ulez

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The writer is director of Public First Consultancy and senior visiting fellow at the London School of Economics

Mayor of London Sadiq Khan’s extension of the UK capital’s ultra-low emissions zone (Ulez) was poorly designed and poorly timed. And the Labour party has paid the price — the policy cost them last week’s Uxbridge by-election. Nor is the London mayor alone in causing anger with a road-pricing scheme: New Jersey governor Phil Murphy is threatening to sue New York over its proposed congestion charge. 

But well-designed road pricing is critical to improving local air quality. Good design matters.

Londoners who bought cars in good faith and must replace them are angry. And what a time to hit people, in the midst of a cost of living crisis. No wonder Labour did badly in Uxbridge.

A sensible policy would let people keep their current vehicles, be stricter on replacements without hitting the poor and be much stricter on taxis and minicabs.

We should allow residents to keep their existing car or van, exempt from the outer London Ulez charge. That would, at a stroke, eliminate the anger. Those who work in outer London could also register their car for an exemption. 

We should also allow everyone to drive into the outer London zone a few times a year for free. Allowing people to visit friends and family now and again for free is a sensible concession that will have little effect on air quality.

These proposals will blunt the air quality benefit in the short term. To compensate, we should be much stricter on which cars Londoners can buy. At present, all sorts of badly engineered cars are exempt, despite only creeping under the pollution limits. These cars are part of the problem, not part of the solution.

Specifically, when people buy a replacement car, it should meet two standards for exemption. As now, it must meet an absolute emissions standard. That car does not have to be new — as a rule of thumb petrols since 2006 and diesels from 2016 are compliant, as well as some older cars. Additionally, the car must be in the cleanest half of cars manufactured that year. For example, new cars can emit up to 80mg/km of NOx and all are currently exempt. But half of petrol and diesel cars emit 21mg or less. Given that, why welcome into London new cars emitting 30, 40, 50, or even more NOx? If they all emitted 21mg or less, nitrogen oxide emissions from this group would fall by over half. Certainly, people buying a new car get a little less choice, but their options would still be plentiful.

Not everyone can afford a new car. Thankfully the “cleaner half” rule works just as well for older cars. In 2016, for example, the cleaner half rule would give us a threshold of 36mg of NOx, rather than 80mg. Again, 36mg gives a lot of choice, while cutting emissions from 2016 cars by almost half.

The same rules should apply to vans. Allowing drivers to keep their current vehicle, and requiring them to buy one according to the “cleaner half” rule when they replace it, is a pragmatic solution that improves air quality and bankrupts no one. And, unlike a scrappage scheme, it does not cost money. 

The only exception to the “cleaner half” rule should be taxis and minicabs. These are high-mileage cars. A growing proportion of London’s black cabs is already “range extender” electric cars, and electric minicabs are increasingly common.

All black cabs should be range-extender electrics and all minicabs electric within a year. Low-mileage electric cars are available for well under £20,000. Reducing emissions from cars that are on the road all day, every day, matters a lot, so tougher rules for these types of vehicle are entirely appropriate.

This approach would be socially and politically acceptable, improving air quality in ways that London — and other cities around the country and, indeed, the world — need.