An overlooked side effect of ULEZ?
Controversy has also arisen because the original ULEZ zone dating from 2019, a central zone that garnered relatively limited opposition when the charge was first applied, has, since the end of August, been extended to the whole of the capital coming under the mayor’s jurisdiction. This is roughly the area encompassed by the M25 motorway. The extension is huge, covering metropolitan suburbs and incorporating residential areas occupied by some relatively poor home owners more likely to own older petrol and diesel cars that fall foul of the scheme’s extension. It also captures of course those motorists living outside of London who drive into the zone to work, play or shop, again some of whom are not necessarily wealthy. For those residents of London owning an offending vehicle there is the palliative of a subsidised scrappage scheme offering a basic £2,000 for crunching a non-compliant car.
Distributional issues aside, the basic economics of what has been implemented are relatively sound. Whether the charge is pitched at an appropriate level is a different matter. And a complicated matter because motorists also impose another externality, this time associated with traffic congestion, and a specific charge for this applies only to a small central area of London. Arguably, the ULEZ acts also as a proxy charge on road congestion for areas lying outside the centre and this has been alluded to in TfL material. But, putting such detail aside, completely overlooked is a significant anomaly when implementing an emissions charge on a particular part of the transport sector.
Consider first the probable short term behavioural reactions to the extended ULEZ. There will be fewer total journeys both into and within the ULEZ zone, but probably not a great deal fewer. Nevertheless, one hopes that the economic consequences of this reduction was considered during the decision process. Other journeys that were by car will have become instead extra journeys on London’s buses and underground and a few more on overground rail. This modal shift, as it is called by the transport planners, will slightly ease road congestion (an added plus) but will increase loadings and thus crowding on public transport, a disadvantage, or to use economics jargon, a disbenefit. Whether benefits offset disbenefits I will leave others to try to calculate but let us presume it is a score draw when it comes to balancing longer journey times and the discomfort of riding more crowded public transport, against the benefits of slightly less congestion on the roads.
So far so good for the ULEZ scheme. But now the downside. Some of the modal shift, as noted above, will occur because of additional ridership on London’s Tube system, much of which is underground, a characteristic, of course, giving the system its moniker. And there lies a problem that seems to have escaped the attention of most of the media. Parts of the Underground suffer from serious air pollution, discovered following research in 2019 sponsored by the Financial Times. According to the newspaper, the deep Tube is by far the most polluted part of the city because of considerable particulate pollution from metal friction, clothing fibre, and dust in general trapped in the tunnels. And there is a lot of it. Using hundreds of measurements inside carriages within Zone 1, dangerously high levels of pollution were found, particularly on the deeper lines. All the deep lines (Piccadilly, Jubilee, Bakerloo, Northern, Victoria and Central) had particulate PM2.5 levels at least five times higher than the World Health Organization’s safe limit and much higher than average levels on the surface, (generally less than PM1.0) particularly in outer London.
The extra ridership on the Tube due to the ULEZ is no doubt tiny compared with daily numbers using the network; this number, about 5 million people a day, is equivalent to more than half the population of the capital. Tiny the extra numbers may be, but these transferees from road vehicles will have their health risk increased as a result of the ULEZ-induced modal shift. Whether this was considered when calculating the statistical numbers of reduced deaths due to the scheme is unknown, but it is by no means apparent that it was considered.
That leaves a larger issue of the health of regular riders of the London Underground. Using the mayor’s rationale for the ULEZ scheme, should not a similar additional charge be introduced for use of the deep level Tube? At the very least, until it can be shown that action has been taken to reduce PM2.5 to acceptable levels, the mayor should restructure and rebalance public transport fares, reducing those on his managed bus system and the surface running outer tube/overground services, whilst hiking fares for the deep running lines in Zone 1 and 2. A consistent, rational public health approach requires it, and particularly if the mayor is to avoid accusations of being anti-motorist.
David Starkie is on the Executive Board of the Journal of Transport Economics and Policy. Expressed here are his personal opinions.