‘Be more French’: Sir Sadiq urged to cut speed limits during ozone alerts

The Mayor of London should look to the French and impose driving restrictions in the capital during periods of high ozone pollution, the leader of the Greens on the London Assembly has said.

Ozone is a harmful gas at ground level, formed when sunlight reacts with emissions from traffic and industry. London has already seen three high ozone alerts this year, including two during June’s heatwave.

Sir Sadiq told Londoners at the time to avoid idling their engines and burning garden waste, and to consider public transport over a private car where possible.

Green Assembly member Caroline Russell has now asked City Hall to take a leaf out of Paris’s book and deliver clear, firm restrictions during periods of dangerously high pollution.

Lessons from Paris

Earlier in July, speed limits across the Île-de-France were cut by 20km/h – about 12mph – when ozone pollution crossed a set threshold. Other measures available to the authorities there include banning older, more polluting cars from the road.

Russell told the Local Democracy Reporting Service that ozone pollution is still not “well understood” by the average Londoner, but that it has a significant impact on people with lung and heart conditions.

Amber and red

She said City Hall also had work to do to ensure Londoners understood ozone alerts and acted on them. One way to do that would be to use “amber” and “red” warnings – as with heat – rather than the current “moderate” and “high”.

“Because it’s quite complicated to inform residents about it in a digestible way and people can’t see it, not many people talk about it,” she said.

“We’re glad the Mayor warns people about high pollution – but a simpler way of categorising ozone pollution as ‘amber’ or ‘red’ instead of moderate or high means more people would understand.

“The Mayor’s alerts are welcome, but they must be clear enough that every Londoner understands the risks and knows how to protect themselves. Right now, too many people simply do not know what an ozone warning means or that everyday pollution sources, including traffic, can contribute to the problem.

“We need to be a bit more French – in Paris, they issue warnings for high ozone across a really wide area, the equivalent of Greater London, and reduce speed limits while advising people not to drive if possible, because that will lower the scale of the ozone pollution and health impact.

“The Mayor could both implement this system and also think about reducing speed limits when the risk of ozone pollution is high, and advise people not to drive to reduce the likelihood of some Londoners having heart attacks or extreme asthma attacks. Ozone pollution is just another element of the pressure on our health when we have these heatwaves.

“We need to do everything possible to make sure people can trust the air they breathe.”

Mayor’s response

During an exchange with Russell at Mayor’s Question Time this month, Sir Sadiq acknowledged that increasingly hot and sunny summers mean the “conditions that favour ozone formation are increasing”.

The Mayor said he would consider whether the current alert system was “user-friendly” and would look into the benefits of a traffic light system with officials.

On the Parisian system, Sir Sadiq said he was “always happy to learn from other cities if they’re doing things in a more effective way”.