A Compact City for the Wealthy? Continuing Inner London Gentrification and Impacts on Accessibility Inequalities

We have a new paper out in the Journal of Transport Geography- “A compact city for the wealthy? Employment accessibility inequalities between occupational classes in the London metropolitan region 2011“. The paper explores how the increasingly affluent nature of Inner London has improved sustainable travel opportunities for more affluent professional and management classes, while less affluent groups have increasingly been priced out to lower accessibility Outer London locations.

The Continuing Gentrification of Inner London
The gentrification of Inner London was first recorded by Ruth Glass back in the 1960s, with middle class residents moving into largely working class neighbourhoods as London’s economy began its long evolution from manufacturing towards service jobs. This process has continued for decades, ultimately transforming most of Inner London. In the 21st century, some researchers have argued that gentrification has stalled (perhaps because there are few neighbourhoods left to gentrify) or has entered a different phase (e.g. processes such as super-gentrification and new-build gentrification as discussed by Davidson and Lees).

This research uses the Standard Occupational Class data as the basis of measuring social class. This classification was found to correspond to differences in income, as well as to a distinct residential geography. In particular, the three most affluent groups (Management, Professional and Associate Professional) cluster together, resulting in the social geography we can see in the map below using the 2011 Census data. There is a clear clustering of professional classes in Inner-West London, with two prominent radial corridors extending northwards through Camden, Islington and Hampstead; and south-westwards through Kensington, Wandsworth and Richmond. Concentrations of non-professional groups are mainly in Outer London to the east, north-east and west, with only smaller pockets remaining in Inner London. This analysis largely matches the description of Inner London now being dominated by professional classes, with lower income groups increasingly in Outer London (with some exceptions remaining in Inner East and South-East London).

Professional Classes (Manag., Prof. & Assoc. Prof.) Residential Percentage 2011. Data: Census 2011 (Office for National Statistics, 2016).

As well as mapping the 2011 geography of occupational class, we looked at more recent changes to see if gentrification is continuing or has slowed, using the ONS Annual Population Survey. Analysing changes between 2006 and 2016, we found had substantial gentrification had continued in Inner London, as shown in the table below. The Management, Professional and Associate Professional groups all grew as a proportion of the Inner London population, while all other occupational classes fell proportionally (green cells are above the average for the metro region, and orange cells are below the average). Interestingly, the biggest growth was in the Management and Professional classes, rather than the younger Associate Professional class, arguably more in line with super-gentrification processes. In contrast, there are proportional increases in several lower income classes in Outer London.

Sub-Regional Occupational Class Percentage Point Change by Residence 2006–2016 (final 2016 sub-regional percentages in brackets)

We can also explore these changes at the more detailed level of local authorities, and show that even more dramatic changes are occurring at the local level. In the chart below, each Local Authority is shown as a trajectory connecting its position in 2006 to its position in 2016 in relation to the percentage of professional classes and the total working population. Generally, Inner Greater London Authority (GLA) boroughs experience high working population growth combined with large increases in the proportion of professional classes. Boroughs with a long history of gentrification, such as Camden and Islington, are higher up in the chart reaching 70% professional classes, while more recent gentrifiers, such as Lewisham and Southwark, are rapidly gentrifying from a lower base. Outer GLA boroughs also show substantial population growth but with lower levels of change in professional classes, and decline in some cases. The exceptions are mainly in South and South-West London, with Croydon, Sutton and Richmond all gentrifying. Outer Metropolitan Area (OMA) local authorities have a mixed picture, with some increases in professional occupational classes with minimal working population growth; while some lower income towns such as Luton and Harlow are not gentrifying.

Local Authority Trajectories for Combined Percentage of Professional Occupational Classes and Total Working Population for 2006 and 2016. Data Source: Annual Population Survey 2005–2017.

What Impacts Does Inner London Gentrification have on Accessibility to Jobs?
We would expect that the dominance of more affluent classes in Inner London translates into accessibility advantages for these classes, as Inner London has substantially better accessibility opportunities by public transport, walking and cycling. We were particularly interested in accessibility by more affordable travel modes in this research. Bus travel is in general considerably cheaper than other public transport options in London. This is reflected in higher rates of more affordable bus and walking trips by lower income classes in the 2011 Census data. We can see in the table below that the three lowest income classes (6, 7 & 9) have around three times higher rates of bus travel and two times higher rates of walking than the most affluent three classes (1, 2 & 3)-

We used network analysis to analyse accessibility differences (see working paper on accessibility model). The analysis was carried out using the 2011 census data. The box plot below shows the cumulative accessibility to jobs for 60 minutes travel by Car, Public Transport (all modes) and Bus Only for the occupational classes. We can see differences between classes, particularly for public transport and bus trips, though there is also much variation within each class.

GLA 60mins Cumulative Accessibility to Employment by SOC Groups: Absolute Results

The accessibility differences between occupational classes can be more clearly seen by plotting differences between how the average accessibility for each group varies from the average accessibility for the entire working population, as shown below. Note in this chart the accessibility differences are normalised by travel mode, so the differences between travel modes in the chart above are normalised in the chart below. We can see clear consistent accessibility advantages for the top three occupational classes, particularly for more affordable slower modes- walking and cycling. The remaining occupational classes have below average accessibility to jobs, particularly for the more car oriented Skilled Trades and Process groups.

Greater London Authority 60mins Cumulative Accessibility to Employment by SOC Groups: Relative Differences in Occupational Class Mode Means and Mode Means for Total Population

The results for bus and walking modes is a particular accessibility challenge. Accessibility by these more affordable modes is generally low in absolute terms outside of Inner London. For the bus mode, less than half the number of jobs are reachable at typical commute times compared to the full public transport network. Given that lower income groups are the most frequent bus and walking commuters, and that these classes are increasingly being priced out of Inner London, these limitations are a significant accessibility challenge going forward.

What Policies Can Planner follow to Mitigate this?
In terms of transport policy, this research supports efforts to improve the affordability and connectivity of public transport for lower income populations. This is indeed a priority of the current London Mayor Sadiq Khan, who has committed to freezing public transport fares, and has reformed ticketing to allow multiple bus journeys on a single fare. These measures help offset travel costs for lower income residents in Outer London.

The main policy conclusion is the importance of housing policy in influencing accessibility outcomes in the study area. Low and moderate income groups are being priced out of public transport accessible areas. Without a step-change in the delivery of genuinely affordable housing in accessible locations, the increasing dominance of Inner London by professional classes will continue, resulting in greater accessibility inequalities, and likely increased travel costs for lower income classes.

Note on Covid-19 and Travel Inequalities
This research was completed in 2019, before the recent COVID-19 pandemic. The pandemic has in the short term shut down public transport networks, and greatly disadvantaged millions of city residents around the world. Longer term it is possible that the pandemic will reduce the attraction of inner city areas such as Inner London, due to perceived risk of future pandemics as well as the acceleration of telecommuting and home-working trends. The overall effect could be to slow gentrification processes, although this is difficult to predict. The alternative view is that  London will recover and adapt as it has done following many crises in the past. East Asian metropolises offer a good model of how to built resilience following their response to the earlier SARS and MERS outbreaks.

The wider economic impacts are clearly also important. Certainly we are in line for a very large recession, hitting important sectors such as tourism and hospitality. More specifically in London, the recession may hit development viability for affordable housing, and is a real headache for public transport operators. Transport for London was in financial trouble before the crisis, and is currently dependent on government bailouts to keep running. This will likely curtail the ability of the Mayor to maintain lower public transport fares, and so impact the kind of transport accessibility inequalities this paper discusses.




Planning a Cycling Revolution for Post-Lockdown London

London and the UK as a whole have been severely affected by the Covid-19 pandemic, creating multiple health, social and economic crises. Social distancing requirements have drastically reduced the safe capacity of public transport services. The London Mayor and Transport for London (TfL) have quickly responded with a radical plan for transforming Inner London into a walking and cycling city, with major streetspace reallocation and restrictions on car use. Where should this new active travel infrastructure be prioritised? Will it substantially change travel behaviour for the better? This article looks at plans for new cycling infrastructure in Inner London, and includes recent UCL research by Nicolas Palominos.

The Green Active Travel Response to the Covid-19 Pandemic
The concentration of people, activity and global connections in cities is normally their greatest asset, yet now is the source of acute risk and vulnerability during the coronavirus pandemic. Rail, metro and bus systems enable millions of daily trips to be made efficiently and sustainably, but their crowded nature is incompatible with social distancing. Recent estimates of how many passengers can safely use buses, trains and metro systems in London while enforcing a 2 metre social distancing rule are around 15% of full capacity. This restriction is devastating for transit cities to function, preventing people getting to work, school and basic services; as well as crippling the fares revenue for public transport providers. Although there are plausible scenarios where the 15% limit could be moderately relaxed (such as through mandatory mask-wearing and temperature screening, or an adjustment of the UK social distancing rules to 1.5m/1m) we are effectively looking at months (in the worst case years) with public transport operating at a severely reduced capacity.

With public transport now hampered for the short-to-medium term, there is a real danger that there will be a big increase in car use as lockdown restrictions are eased, undoing much of the recent progress towards sustainable cities and tackling urban problems of congestion, poor air quality, carbon emissions and obesity. The alternative is to dramatically increase walking and cycling through a major reallocation of street space to these active travel modes. Measures for new cycle and pedestrian lanes have recently been proposed by many cities including Milan, Paris, Brussels and Bogota, and are being widely discussed in many more. The aim is to provide safe and healthy travel alternatives to increased car use, and to enable cities to continue to function with public transport restrictions. London Mayor Sadiq Khan has joined these progressive cities by advocating an active travel transformation for London with the Streetspace for London plan.

London’s Fragmented Cycle Routes
Cities that have achieved very high rates of cycling, such as Amsterdam and Copenhagen, have done so with comprehensive networks of segregated cycle lanes, allowing all residents to cycle safely, not just experienced cyclists. London has been struggling to catch up with these cities, and still has a fragmented and incomplete network of cycle lanes. The map below shows Inner London cycle lane data in 2019. The dark blue lines are physically segregated cycle lanes (i.e. a physical barrier between the cycle lane and the road). These are mainly found on CS2 (Cycle Superhighway 2) in East London, CS3 (the only complete East-West route through Central London), and parts of CW6 (Cycleway 6) which is the main north-south link across Blackfriars Bridge that has some sections in Central London that are still under construction.

Outside of these segregated routes there is a scattered patchwork of cycle lanes that are based on road markings without a physical barrier with the carriageway, shown in light blue on the map. There are also bus lanes on many major roads (dark red on the map) which offer some protection for cyclists, but are a long way from the safety of fully segregated lanes. Overall Inner London’s cycle network has many gaps that need filled, particularly in Central, West, North-West, North-East and South-East London. This infrastructure gap sits in sharp contrast to the aim of drastically increasing cycling during the post-lockdown period. The lack of segregated routes increases the risk of cycle collisions with cars, and will discourage public transport users from making the switch to cycling.

The Proposals from the Mayor and TfL
In the Streetspace for London plan, the Mayor has proposed developing a network of new walking and cycling routes to allow Londoners to walk and cycle while social distancing, and to redirect public transport trips to active travel rather than driving. Cycling will be critical for public transport substitution, as most tube and bus journeys are 4-10km, considerably longer than typical walking distances (discussed more below). Given the fragmented nature of current cycle routes, major changes and interventions are required to achieve these aims.

The highly ambitious nature of the proposals were made clear last week with a major plan for new Car Free routes to be introduced in the City of London (below). This plan would transform many of London’s busiest roads into bus, cycling and walking corridors, radically improving cycle access across Central London, particularly to major rail stations. It includes:

  • Completing Cycleway 6 with a car free Farringdon Road leading to Kings Cross Station;
  • A car free Waterloo Bridge, leading to a whole new car free north-south route via Kingsway and Southampton Row to Euston Station;
  • A car free London Bridge, leading to two segregated routes, the first via Bank to Moorgate, and and the second via Bisohopsgate to Liverpool Street station;
  • Upgraded east-west routes, with a car free Theobalds Road to Old Street; and improved cycle provision on High Holborn and Cheapside (could this be extended west to Oxford Street, and east to meet Cycleway 2 at Aldgate?);

These proposals show a comprehensive commitment to the active travel plan, and include major restrictions on driving to make this happen. In addition to the Car Free routes, the Congestion Charge and low emission zones have been reinstated, and the cost of the Congestion Charge will rise to £15, and hours of operation extended to 7am-10pm 7 days a week.

The Central London plan also shows that the City of London (the borough authority that controls London’s financial district) share the Mayor’s vision, as this proposal can only happen with their close cooperation. Indeed the City of London had already developed a longer term plan for removing cars from most of the City, and this proposal fits closely with their vision.

While Central London is vital for the Mayor’s active travel plans, the vast majority of journeys begin outside the City. Clearly a much wider vision for all of London is needed. TfL have stated they will create 30km of new permanent cycle lanes this summer. They have released a London-wide map of proposed new ‘Streetspace Routes’ on their website (below). While this map is very much in development (it does not yet have the City of London routes above added), there are several very significant proposals, including-

  • Segregated cycle lanes on Euston Road- a vital busy highway connecting major rail stations (Paddington, Euston, Kings Cross), as well as linking to the north-south routes in the above Central London map. The Euston Road proposal extends all the way west to Acton;
  • adding a further set of new routes in West London, including Cycleway 9 from Hounslow to Brentford and Kensington Olympia;
  • speeding up the completion of CW4 from London Bridge to Greenwich and Woolwich in South East London;
  • improving CS7 to Brixton and Clapham in South West London;
  • completing a North-West link from Regents Park to Golders Green;
  • adding a new link from Hackney to Canary Wharf;

Predicting Where Cycling Demand is Likely to be Highest
While there are lots of excellent proposals in the TfL map above, it does not yet form a complete network (it also does not differentiate between the quality of existing cycle routes which are highly variable). We can use network analysis to consider where cycling demand is likely to be highest, and where new infrastructure should be prioritised. The analysis below by Nicolas Palominos at CASA is based on shortest paths between underground and rail stations, and is indicative of where active travel trips are most likely to be made if passengers are prevented from taking the tube/bus/train (see full working paper here). The map highlights the core network of Inner London’s most prominent links, including its oldest Roman Roads- Edgware Road, Kingsway, Oxford Street. Promisingly, there is considerable overlap between these critical shortest path routes and the cycle network proposals by TfL. We can see the importance of the new north-south Waterloo Bridge-Southampton Row link for example; Euston Road’s importance is clearly shown; as is Theobald’s Road to Old Street. TfL have completed similar analysis in their Strategic Cycling Analysis from 2017, and we can assume this is guiding their plans.

There are however some important links missing highlighted through the network analysis. The most significant missing link is London’s most important east-west route that runs along Hyde Park through Oxford Street all the way to Cheapside and the City (following the route of the Central Line). The City of London proposals cover the eastern section of this vital route, from High Holborn to Bank. There needs to be similar cycling upgrades for the western section: Oxford Street, Bayswater Road and Holland Park Avenue. This intervention requires the Mayor to cooperate closely with the City of Westminster authority. Politically this is difficult, as Westminster has been blocking high profile proposals from the mayor in recent years, most notably the pedestrianisation of Oxford Street. Coming to some agreement will be essential for the western expansion of the cycle network to be joined together effectively.

Other key routes that are not yet part of the proposals include Edgware Road; Peckham Road; Essex Road; Old Kent Road; City Road; Commercial Street; Kingsland Road; and Seven Sisters Road amongst others. These are discussed further in the working paper. Edgware Road is currently the main north-south driving route that avoids the Congestion Charge, and giving space to cycling would be difficult to implement here (although Park Lane is included in TfL’s plans, and indeed the Park Lane cycle lane is already installed on the western carriageway adjacent to Hyde park). The Swiss Cottage to Golders Green link looks like the proposed north-west alternative to Edgware Road, and would benefit from completion through Regents Park to the Euston Road link. The network analysis strongly agrees with the Euston Road cycle provision, though in this analysis this critical link continues further to Pentonville Road, City Road and Commercial Street encircling the City.

Overall, the TfL Streetspace proposals look very promising, and need to be further linked together and expanded as discussions with more boroughs continue. This will also need much more emphasis on Outer London centres and local shopping and school routes, important topics which are not covered in this article.

Estimating the Number of Cycling and Walking Trips Post-Lockdown
What might the the number of trips by different travel modes in London look like in the coming months? This is highly uncertain. Some modelling figures from Transport for London quoted in press releases are anticipating radical changes in behaviour, up to a ten times increase in cycling trips, and up to a five times increase in walking trips. Are these figures realistic?

The chart below shows the distribution of trips pre-lockdown (from TfL Travel in London Report 12), and a series of post-lockdown guesstimate scenarios to discuss where we might be heading. Normally in London we are looking at around 27 million trips per day, with 9.5m by transit, 10m by car, 7m by walking and 0.7m by cycling. The lock-down figures in the chart below are based on TfL’s statement that underground passengers have been at 5% of normal levels, and car traffic has been radically reduced (though is picking up more recently). We don’t know overall walking and cycling levels during lock-down, but given workplaces, schools and most shops are closed, they have likely fallen.

What happens next is massively uncertain. During the lockdown, everyone except for key workers have been staying at home. This will change as the lockdown lifts, depending on the percentage of people who continue to stay at home. There are various reasons for continuing to stay at home: working from home; looking after children at home (particularly if schools remain closed or are only partially opened); and people who are furloughed or become unemployed. Two scenarios are shown above, with 50% of people continuing to stay at home and 20% of people continuing to stay at home. The 50% figure is likely to be closer to reality for at the least the next few months, with infection rates still significant and most schools and workplaces still closed.

Using the 15% social distancing capacity limit estimated by TfL, we can see that 8 million daily public transport trips (or 4 million return trips) can no longer be made. The question then is what happens to these trips. The Active Travel scenarios shown above are based on a big increase in cycling and walking trips remaining constant or increasing. The Car Travel scenarios in contrast estimate what will happen if these trips do not switch to active travel, and significantly more driving occurs. This results in more car trips than pre-lockdown and consequent problems of increased congestion and air pollution.

How realistic is it to assume that public transport trips could switch to active travel modes? One basic way to consider this is using average trip distances by travel mode, as shown below. It is clear that National Rail trips are often long distance, and substitution with active travel is likely going to be unrealistic for most of these trips. This seems to be the assumption in the TfL plans, as the Car Free Streespace corridors prioritise linking up the biggest mainline railway stations. The idea is that mainline rail trips will change the next leg of their journey to cycling and walking, rather than tube or bus. There will likely be significantly more demand for cycle parking/hire facilities at stations and for taking bikes on trains.

The most popular public transport mode in London is the bus, and bus trip lengths are very close to average cycling trip lengths, so prospects for active travel substitution are much better for these trips. Average Underground distances of just under 10km are potentially workable as cycling trips of around 30-40 minutes (or quicker with electric modes), so some substitution is possible for these trips. The network analysis in the working paper found average trip lengths for shortest path between stations in Inner London to be just over 10km. The extent to which public transport trips can be substituted with walking trips is highly questionable for distances above 5km, as this will take most pedestrians an hour or more. The average walking trip in London is less than 1km. This likely makes cycling the key active travel mode for most public transport substitution, as well as there being significant opportunities for expanding recent micromobility options such as e-bikes and e-scooters.

The Mayor and Transport for London have proposed a radical Streetspace for London plan to redirect trips to walking and cycling as we move out of lockdown, and try to avoid a huge increase in car trips due to social-distancing capacity limits placed on public transport services. The Mayor and his team are essentially using this crisis to rapidly speed up active travel plans for London that were on the drawing board for the next decade. These plans are not empty words, they are backed up with a comprehensive transformation of many Central London routes to car free routes, as well as further restrictions on car use through the Congestion Charge. These measures are already being implemented.

At present, the proposed cycle network has lots of excellent proposals, yet remains incomplete, missing key links such as Oxford Street, as well as lacking proposals for linking Outer London centres. The proposals require support from London’s borough councils to be developed, and so far have support from key boroughs such as the City of London (with other pro-cycling boroughs such as Hackney and Camden also likely to be supportive). Hopefully more agreements will be reached with boroughs such as Wesminster, otherwise the new streetspace links will miss key parts of Inner London.

What can the next mayor do to tackle London’s hazardous air pollution?

If news emerged that a virus was killing thousands of vulnerable Londoners every year then there would justifiably be public alarm, followed by swift political action. Yet the impacts of this imaginary scenario are similar to what air pollution has been inflicting on Londoners for many years, while the political response has been slow. According to the most up-to-date and comprehensive research, air pollution reduces Londoners’ life expectancy equivalent to the death of 9,400 people of average age every year (5,900 due to NO2 and 3,500 due to PM2.5) as well as exacerbating respiratory diseases in vulnerable populations. Despite the severity of these impacts, it has become standard practice over the last decade for national government and the London Mayor to gloss-over the problem, downplay continued breaches of European law, and for politicians to delay taking any significant responses.

The current London mayor, Boris Johnson, has been slow to face up to the challenge. His tenure began by removing the western extension to the Congestion Charging Zone, thus increasing vehicle numbers in Inner West London, and opting out of using the Congestion Charge to tax the most polluting vehicles. This would have boosted the adoption of hybrid and electric vehicles (still only a meagre 1% of new cars) and reduced heavy emitters in Central London. Furthermore Johnson has not succeeded in comprehensively upgrading London’s bus and taxi fleet to hybrid and electric vehicles, instead embarking on an expensive new Routemaster project which still produces substantial emissions and currently makes up a minority of the overwhelmingly diesel bus fleet.

NO2 Annual concentration in London 2010, modelled by the London Atmospheric Emissions Inventory. All of Inner London and many major roads in Outer London greatly exceed the EU limit.
NO2 Annual concentration in London 2010, modelled by the London Atmospheric Emissions Inventory. All of Inner London and many major roads in Outer London greatly exceed the EU limit.

As recently as 2014, Johnson was still playing down the air pollution problem, in the face of strong evidence of London’s busiest streets like Oxford Street having amongst the highest concentrations of nitrogen dioxide in the world. For much of his time as mayor, he has assumed that the issue is not a public priority, and that driver and transport demands trump health concerns. This approach looks more questionable by the day. Evidence continues to mount that air quality is comparable in its health impacts to passive smoking and obesity. The consequences of the current Volkswagen scandal are still emerging as the huge gap between the advertised environmental performance of diesel vehicles and what we are really breathing in our cities is revealed. And the full costs of poor air quality are only beginning to be counted (e.g. billions of pounds added to NHS bills).

Looking to the future, London must now tackle the air pollution problem with a new mayor in the upcoming 2016 elections. The scope for change looks positive, as the main candidates on both the left and right have been openly discussing the need for change. What then could a new mayor do to address air quality and improve the health of Londoners?

Pricing Out Polluting Vehicles with the Ultra Low Emission Zone
To be fair to Boris Johnson, he did finally respond to pressure and announce a significant air pollution policy in 2013, dubbed the ‘Ultra-Low Emissions Zone‘. The ULEZ is set to come into effect in 2020 and essentially uses the Congestion Charging infrastructure to tackle the most polluting vehicles (similar to what Livingstone proposed way back in 2006). The question is whether the ULEZ goes far enough. It’s based on Euro emission standards, which measure NO2 and PM10/2.5 as well as CO2 emissions. It correctly targets diesel vehicles, requiring them to meet the Euro 6 standard, which only came into force in September 2015, so almost all current diesels on the road would have to change or pay the charge. This means that the main source of NO2 emissions will be appropriately targeted.

The current Congestion Charge boundary will be the basis of the Ultra Low Emissions Zone (map by TfL).
The current Congestion Charge boundary will be the basis of the Ultra Low Emissions Zone (map by TfL).

There are limitations however. The charge is only going to be £11.50 (except for large buses and HGVs), so it likely many diesel users will continue to drive into Central London and pay the charge. Furthermore the ULEZ will only affect Central London; the rules on diesel taxis and private hire vehicles have not been decided; and ULEZ zone residents get an overly generous exemption until 2023.

The next mayor will have a number of options that could be pursued if they want to be bolder than Johnson’s ULEZ proposal. These include increasing the ULEZ charge and/or Congestion Charge, bringing the ULEZ implementation forward to an earlier date, and potentially reintroducing the Congestion Charge Western Extension. All of these would make significant improvements to air quality, but would be controversial with drivers, many of whom were mis-sold diesel vehicles in the past as a supposedly environmentally benign option. The mayor may also want to re-examine the wider Low Emission Zone (LEZ) that tackles very polluting vehicles entering the whole of Greater London, as this affects the entire city and has not changed since 2012.

Euston Road, one of London's busiest and most polluted routes with NO2 annual concentrations typically twice the EU limit (photo by D Smith).
Euston Road, one of London’s busiest and most polluted routes with NO2 annual concentrations typically twice the EU limit (photo by D Smith).

Banning Diesel?
A more radical approach currently being proposed for Paris is to ban diesel cars all together. This would certainly make a huge improvement to air quality. The problem for London would be that the city’s bus and taxi fleet would fail this restriction, and there would likely be a backlash from thousands of car and van drivers. This would be a very confrontational approach for a new mayor.

The more pragmatic solution for London would be to work with the ULEZ framework, considering stricter measures and higher charges, and implementing the policy earlier. One very important issue for the new mayor is emerging from the current Volkswagen emissions scandal. It looks like the latest Euro 6 diesels produce significantly higher NO2 emissions in real world driving conditions compared to the misleading testing conditions. If this is the case then the proposed ULEZ will be much less effective in improving air quality (as Euro 6 diesels will be exempt from the charge). The ULEZ may have to charge all diesel vehicles, regardless of their Euro rating. This decision would need to made very early, so that there is sufficient time for car users to adjust behaviours accordingly.

Pedestrianising Streets and Upgrading the Bus Fleet
Oxford Street is London’s busiest pedestrian street and has some of the worst NO2 pollution in Europe. A response that is gaining popularity is to pedestrianise the whole street. Certainly this would be an iconic change to both the image of London, and to the experience of the city for thousands of Londoners and tourists. The challenge for this measure is avoiding creating bus jams at either end of Oxford Street, and handling the extra demand levels that would be placed on the already congested Central Line. These challenges are not necessarily permanent however, as the arrival of Crossrail in 2018 (which follows the west to east Central Line route through Inner London) has been described as a ‘game changer’ that makes pedestrianising Oxford Street a realistic option. The new mayor should certainly pursue this possibility.

The wider challenge for the mayor is not to just think about Oxford Street, but to accelerate the upgrading of the entire bus and taxi fleet towards zero emission vehicles and develop wider pedestrianisation policies. This would improve air quality for all of London’s high streets. London is still at the trial stage of pure electric double-decker buses, which represents disappointingly slow progress considering how long we have known about air pollution problems. There’s been better progress on electric/hydrogen single-deckers. Considerable investment will be needed to upgrade the bus fleet, with decision-making based on real evidence and value-for-money. Johnson’s Routemaster project has failed both these criteria, and better leadership is now required.

Heathrow Third Runway
All the main candidates for the London Mayor oppose the expansion of Heathrow, with air pollution alongside noise pollution amongst the most important factors. You can see how Heathrow already dramatically increases emissions in West London in the NO2 annual concentration map at the top of this article using the London Atmospheric Emissions Inventory data. This is due both to emissions for aircraft engines, and the thousands of cars driving to and from Heathrow everyday. The challenge will be how effectively the new mayor can challenge the UK government to reject the Heathrow expansion option.

Overall, the issue of air pollution has gained unprecedented prominence as we approach the 2016 mayoral elections. The main candidates need to respond accordingly in their manifesto commitments, with London having a lot of catching up to do after eight years of little change. It will be interesting to see which candidates are prepared to be bolder.