Time to start limiting the use of the dirtiest vehicles

The London Ultra Low Emission Zone (ULEZ) has been somewhat controversial, or more accurately, has upset owners of the dirtiest cars on London's streets and offered several right-wing borough councils the opportunity to attack Mayor Sadiq Kahn by dragging the legislation into court.

Aside from this though, it has been a well recieved measure which succeeds in its aim of getting the most polluting vehicles off London's streets, creating a healthier environment for all.

Other cities around the world need to follow suit. Research has shown that air pollution has a significant effect on respiratory disease incidence for people who live and work in cities, and makes life worse for those who already suffer.

Once we agree that it makes sense to limit the use of vehicles which worsen air quality on our city's streets, it isn't a great jump to argue that we should be limiting access to those vehicles which produce significant carbon emissions too. By creating an exclusion which limits access to cities for the most environmentally unfriendly vehicles - starting with anything which emits more than, say, 400g/km and then gradually reducing that number - we immediately start to limit greenhouse gases entering the atmosphere and contributing to global warming.

Or to put it another way, it will be much easier to limit the mileage of highly polluting fossil fuel vehicles than it would be to ban them outright from day one. If we reduce the usage of these vehicles by 25% that has a significant impact on overall emissions from road transport. By increasing number of the vehicles which fall under this umbrella each year the improvements are cumulative.

Using the money raised by the ULEZ, the Mayor of London has been able to create a number of schemes to help people get out of their vehicles and into cleaner ones. Extending that further and creating incentives for people to give up their cars entirely would be a good next step. The quality of London's public transport infrastructure lays the foundations for a world-beating service.

Restrictions are never going to be popular, but change is not something which people embrace without some compulsion to do so.