TAPAS.network | 18 June 2024 | Commentary | Mark Frost

London mayor has a big target for cutting carbon emissions - he needs big ideas to achieve it. Here are five to start with

Phil Goodwin

Newly re-elected London Mayor Sadiq Khan has set an ambitious 2030 net zero target for the capital, but how will he achieve it? Mark Frost suggests that better bus priority in partnership with boroughs, a far-reaching travel behaviour change programme, strategic kerbside management and measures to cut freight emissions are all key measures he should pursue.

IN THE RUN-UP to last month’s mayoral election in London, the extension of the ULEZ ( Ultra Low Emission Zone) to outer London boroughs sparked much fire and fury on social media as well as damning press coverage. It appeared to kick similar radical new measures to reduce transport carbon emissions firmly off the agenda . In the event, it seemingly had little impact on the result, with Labour’s Sadiq Khan convincingly re-elected for a third term.

Pleased though he no doubt was with the election result, Khan now faces a monumental transport challenge that he’ll have to get to grips with quickly as his manifesto recommitted to the capital achieving net zero by 2030 - only five and half years away.

The key analysis of how to achieve that ambitious goal was set out in a report Pathways to Net Zero Carbon by 2030 for the Greater London Authority (GLA) by Element Energy in 2022. There’s a lot in that work, but the key takeaway for most transport planners was that kilometres travelled by vehicles in the city needs to reduce by 27% by 2030 if the Mayor is to get anywhere close to his Net Zero target.

That feels herculean, and the reality is that it’s probably even worse than thought in 2022, given that this analysis also assumed a ban on new internal combustion engine (ICE) vehicles would take effect in 2030, thereby accelerating a shift towards electric vehicles (EVs) for those trips that continued to be made by cars and vans. That national target has since been moved to 2035, by Rishi Sunak’s Conservative Government, and whilst Labour seems set to reverse this if they win the impending General Election, the temporary watering down of that pledge will still have slowed progress at a time when literally every day counts if 2030 is to be deemed in any way credible.

To make things even trickier, in response to the (mis)perceived electoral threat of his opponent Susan Hall, Khan has repeatedly and very publicly ruled out a pay per mile charge - the only tool most experts agree would be likely to get us anywhere near the size of reduction required in the timescales stated.


The Mayor’s bruising battles over the ULEZ extension appear to have seen off any desire to take a more strategic approach to managing moving traffic

He also said he won’t change the ULEZ standards during his new electoral term. It’s debatable whether this definitively rules out the introduction of something like a cordon charge (congestion charge lite) at the inner or outer London ULEZ boundary, but clearly that would feel somewhat against the spirit of his words in the manifesto. Possibly a zero-emission zone in the Congestion Charge area could still be progressed, building on the recent announcement of such a zone (albeit much smaller) in Stockholm and an even smaller (but potentially set to grow) one in Oxford - but even this would no doubt elicit cries of betrayal. After a bruising time with ULEZ, the implementation of which has been described by the Mayor as the “toughest challenge I’ve faced in the 30 years I’ve held public office,” would there be the energy in the tank or political capital left in the bank for this? I’m not so sure. Given the political heat he was facing, this absolutism was perhaps understandable, and therefore the allegation from the Green Party that this was a “cowardly” way to do politics is maybe a little unfair. But they are undoubtedly right that these self-imposed manifesto red lines on further action put a rather large dent in his ability to achieve his goals in the timescales aimed for.


Superloop has proved that renewed focus on bus service innovation is working, with patronage on the network growing above the average overall.

So, shorn of his transport policy big guns, what’s a newly-minted Mayor of a global city to do to fulfil his manifesto pledge? Are his options likely to be similar to those available to other major metropolitan areas facing such challenges -or can he come up with some new London-specific tricks?

First up, it would be wrong to say that Khan’s election manifesto was wholly silent on how to achieve this - there’s some undeniably good stuff in there.

Most car trips, and therefore transport-related carbon emissions, are caused by trips to, from, or in outer London. Creating better alternative sustainable transport options, particularly for those longer distance car trips, will be essential if we’re to get anywhere near net zero.

Delivering on buses, rail, EVs and streets - it’s a good start

Finishing Superloop, the new limited-stop express bus network that circles the capital, and the promise of a possible Superloop 2, is therefore a great start. There seems to be real evidence that this renewed focus on bus service innovation is bearing fruit – patronage of all Superloop routes seems to be growing above the network average.

More importantly, this is the kind of intervention that can be delivered genuinely quickly and can help with that 2030 deadline (though to note that less than a year from inception to roll-out, as we saw with the first Superloop routes, is probably too quick, and cost a lot more than it should as it had to be driven through variations to existing bus service contracts etc).

There’s some other good innovation happening slightly more under the radar, such as the Bus Sense programme, which looks to better coordinate planned and emergency work with bus services to minimize compound delays in particular. This is showing great promise in some central London boroughs in improving reliability and stemming reductions in average speeds. Continuing roll-out of traffic signal technology that prioritises buses also helps. But clever traffic management behind the scenes alone clearly isn’t going to be a silver bullet.

For new services to really achieve their full potential, more will need to be done on bus priority and improving reliability - suggesting a need to direct massive resources to the London boroughs to support this agenda on their patches given that the majority of bus mileage is on roads controlled by the capital’s town halls. We’ve had the concept of mini-Hollands successfully improving conditions for cycling Dutch-style – especially in poster-borough Waltham Forest as reflected upon by John Dales in TAPAS, 5 June 2024. Perhaps we now need mini-Bogotas for buses, echoing that Colombian city’s highly successful Bus Rapid Transit network?!

Achieving a fully electric bus fleet by 2030 is another bold, but not cheap, pledge to fulfil. Buses accounted for 7% of emissions in 2019 (likely around 5% now), so that’s a handy slab of emissions that can be dealt with without a bruising culture war battle. It’s not cheap though, which is why Transport for London continue to talk about 2034 as the delivery date, with 2030 as an aspiration they are still “exploring”. Getting an earlier date across the line will no doubt come at a premium, and that will have opportunity costs for other areas of decarbonisation, which will need careful consideration.

Freezing fares will also help with supporting bus use , but again, care will be required to ensure that this doesn’t have too high of an opportunity cost by eating up budgets. Would working towards matching the £2 national bus fare (which would be worth even more to users in London thanks to the Hopper multi-ride fare) over the course of the next few years really do much to dent demand? And what could that additional revenue unlock? We know journey time savings generate more passengers than fare reductions, so this is a debate we really need to have.


Action on parking can contribute to Net 􏰂ero whilst allowing the beneficial reallocation of kerbspace to other uses such as rain gardens

Moving on from buses, one largely unheralded but potentially game-changing pledge is the renewal of the prospect of further devolution of control over rail services in the south of the city to the Mayor.

As set out in the strategic case for this devolution, the South sub-region is the most car dependent area in London. Car ownership here is also the highest out of London’s five sub-regions – back in 2019 this was by a substantial margin, 9% higher than the second ranked sub-region (West). Car dependency means south London also has the lowest active, efficient and sustainable mode share in London. In short – it’s a good place to go hunting for emission reductions by achieving modal shift. As the roll out of the TfL- run Overground has shown more effectively run suburban railways can pull in the punters - though whether it can extract the required numbers from their cars by that 2030 deadline is debatable. Labour’s recently released manifesto (and surrounding “noise”) suggests that, despite their being alignment between City Hall and Westminster for the first time in more than a decade, approval for this devolution from them seems far from a slam dunk. Assuming July the 4th delivers the result everyone is expecting, there will be a need for the mayor’s team to win this argument quickly if these improvements are going to be online in time to effectively contribute towards his net zero target.

Moving away from public transport, there’s some other good stuff in the mayor’s manifesto too; 40,000 new EV charging points (up from around 15,000 now) will help remove barriers to transition, particularly amongst the around a third of homeowners with no off-street parking to provide their own charging.

And then there’s some chat about road space reallocation, but only in respect to a modest further roll-out of school streets initiatives - “school super zones” - that aim to help make the area in and around schools healthier for children by suppressing traffic . There’s also a commitment to keep spending on cycling infrastructure and a welcome indication that Healthy Streets funding for boroughs and TfL will rise. In a nice and no doubt purposeful symmetry with the EV charging points, 40,000 new cycle parking spaces will also be provided, including many more bike hangars. Whether the latter will be at a cost that people can afford will need to be seen, of course, and I suspect will largely depend on whether TfL make additional funding available to cash strapped town halls to subsidise.

Overall, however, the ULEZ battles, and those over LTNs (Low Traffic Neighbourhoods) appear to have seen off any desire to take a more strategic approach to managing moving traffic, and there is no radical plan for tackling traffic flow across the city to remove through-traffic on residential roads ( like strategies we have seen in Birmingham, Edinburgh or Oxford for example). Indeed, as the Greens note, new road links supported by the Mayor like Silvertown Tunnel might well actually induce more traffic, although tolling here and at Blackwall will at least dampen that a little.

Whilst this perceived lack of ambition on local traffic reduction upsets some campaigners, the focus on such schemes might be overplayed from a purely transport decarbonisation perspective. Generally, modal filters are considered to impact largely on shorter, local trips. As part of work commissioned under the London Councils led Climate Change programme, consultants City Science has estimated that such trips (under five miles) might be responsible for only around 18% of total carbon emissions in the city. If we make a big jump up to include all trips under 10 miles, this allows you to bring this figure up to around 38%. However, the number of people that could be persuaded to use active travel to cover such distances, even with some electrical assistance, is debatable.

Low Traffic Neighbourhoods, particularly if delivered strategically alongside complementary measures such as improved public transport journey times or shared transport like car clubs or micromobility options, may have a bigger impact on those longer trips if they help reduce overall car ownership, but the jury is still out on this (notwithstanding the seemingly promising results from places like Waltham Forest). This is not to say they can’t have very positive local impacts on wellbeing, safety and the like, but the carbon reduction case for such interventions is perhaps less strong.

All in all, though, it’s not a bad list of transport plans and pledges that Sadiq Khan has put forward for his third term as Mayor, but it arguably falls short in the face of that big 2030 Net Zero target. I therefore thought it would be a useful exercise to start a conversation about what more the Mayor could do within the policy envelope open to him that could put a bigger dent in those emission figures.

To kick that off here’s five big ideas that I believe could significantly address emissions; could be picked up and progressed in the timeframe the Mayor is staring at; and, importantly, still be within the spirit of the manifesto he’s just been elected on. These are:-

1. Adopt a strategic citywide parking policy

For all the hoo-ha around dealing with moving vehicles that ULEZ caused, we have been busy pricing stationary vehicles for decades. As a famous saying sort of goes, no one likes paying for parking or sex - but at least in the case of the former the need to cough up for your bit of tarmac or parking bay is relatively routine and, in the most cases, largely uncontroversial.

However, this is almost always considered a relatively low-level operational element of highway management and seldom used as a wider strategic policy tool. There are exceptions to this, and those that follow me on social media will know that I’m hugely impressed by the Lambeth Kerbside Strategy as a bold new vision for arguably the most valuable asset the council owns and controls. The strategy sets out a pathway to a transformative reallocation of around 25% of their kerb space to more sustainable uses (up from c6% at the moment, by their own definition).

Camden Council is also pushing forward with new parking policies and charging regimes that seek to move the dial on car ownership and clean up the fleet. A permit eligibility “scrappage scheme” that allows those who voluntarily give up their right to a permit to access discounts on car clubs is a particular innovation. There is a need to support the adoption of these sort of initiatives more widely across London, and a particular requirement to develop an approach that will be effective in outer London boroughs where car use and trip lengths (and so carbon emissions) are higher.

Given the relative bounty of alternatives to the private car in London, it is odd that Workplace Parking Levy (WPL) hasn’t been more widely adopted in the capital since it was enabled in the Transport Act 2000. After a flurry of initial activity back in the last decade, including in my old hood of Hounslow, things have now gone quiet. Taking an active lead on this in partnership with key boroughs to define a set of trailblazer projects that fuse a positive car restraint policy with the unique ability that WPL has to also fund new sustainable travel infrastructure should be a priority for the Mayor. Rather than thinking of these things as big bang, whole city or whole borough type approaches, it would be better to think of them as smaller, targeted interventions at areas where there are congestion problems and near-market sustainable transport solutions that might deal with those. In this way they could be seen more like an enhanced Controlled Parking Zone (CPZ) perhaps. Should a new Labour government arrive, with a promise of a radical programme of decentralization, could the need for Secretary of State sign-off also be removed, enabling such schemes to move forward with greater pace? Once a couple of WPL schemes are across the line, I suspect the approach will snowball and become a widely adopted tool, as indeed CPZs have in last couple of decades. The key is getting those proof of concepts in, and proving the world doesn’t end the day after.

Clearly, conversion to electric vehicles is key to net zero – and the pace of the move away from EVs will be the largest single determinant of whether the Mayor hits his target. Given the lack of any changes to ULEZ, parking management will play the most important role in facilitating this. As noted above, the manifesto is looking for at least a doublingin charging points, most of which will need to find a home at the kerbside. There is also scope for progressive parking tariffs (whether for sessional or resident parking permits) to nudge people more quickly towards EVs.


There needs to be proper recognition of the role of shared cars and a citywide approach to the provision of mobility hubs

There’s lots more that could be done on parking, much of it outlined in a Transport Planning Society position paper Just the Ticket! released earlier this year. This includes the use of a ‘utility pricing’ approach that means prices paid for parking better reflect the negative externalities caused by that individual trip - e.g. having higher charges for those travelling in the peak as a proxy for tackling congestion.

In his excellent book Good to Go? Decarbonising travel after the Pandemic, industry legend David Metz pointed at parking policy as being possibly the most effective tool in cutting emissions in the short term. It’s time we listened to such sage advice and start acting on it.

2. Create a new partnership on transport with wider South East

Everyone needs good neighbours said a wise Antipodean singer once, but London hasn’t necessarily been the greatest in Khan’s last term. Ramming through ULEZ without any provision for support for low-income residents outside of the GLA area was particularly un-neighbourly. So, a bit of charm and time spent rebuilding that relationship is now warranted.

A hard-nosed assessment would also lead to the conclusion that carbon has little respect for the GLA boundary and trips across it are more likely to be by car, longer distance and so more polluting. It is good to see increasing interest in outer London transport in City Hall, poked by insightful analysis by organisations like Centre for London, but when thinking about carbon emissions it’s not enough to look only at zones 3-6. It’s essential to think about the wider functional economic area beyond the city limits that drives actual travel behaviour.

In the face of that 2030 target, now is the time to rebuild those cross-boundary relationships with some proper strategic transport planning between City Hall and the wider southeast with a real focus on delivering modal shift and cutting carbon. The Mayor might consider demonstrating good practice in a couple of exemplar focus areas e.g. around existing outer London opportunity areas such as Heathrow, Lee Valley, Thames Estuary etc. to explore new ways of working and identify win:win outcomes for modal shift and decarbonisation that could be achieved through better collaboration.By way of practical example of what could be produced, boundary Local Cycling & Walking Infrastructure Plans (LCWIP) or Bus Service Improvement Plans (BSIP) such as those recently developed for the Heathrow area by the Heathrow Strategic Planning Group and the Heathrow Area Transport Forum might be a good place to start.

Over the last decade or more there has been austerity-inspired retrenchment of the level of partnership in these geographies. This has led to general stagnation of rail service provision, reduction in bus mileage and cycle lanes that stop at arbitrary administrative borders. After years of neglect my hypothesis is that there’s a lot of low hanging fruit here in terms of modal shift, potentially achievable from relatively modest levels of investment.

3. Get people on board via creative travel behaviour change programmes

I started my career in this fabulous industry as a school travel advisor at a time where there was endless enthusiasm and optimism for what behaviour change programmes could do in mitigating negative externalities from travel. Looking back, I think this approach probably reached its zenith during the hugely successful Olympic Games in 2012, a success that was in no small part down to a brilliant travel demand management campaign that kept the capital moving.

In partnership with London Strategic Transport Forum (part of London Technical Advisor’s Group), consultancy Steer recently undertook a review of behaviour change activity in the capital. The emerging findings are sobering for those that entered the industry in the noughties when this was such a key tool in a transport planners armoury. Much expertise and capacity has been lost, and the networks that developed effective good practice and disseminated these are largely defunct. This agenda needs to be picked up again - seeing net zero by 2030 as an Olympic moment perhaps and galvanizing public action behind that in the way we made 2012 such a success to London and indeed UK PLC.

Some key tools in this space could include:

  • Widespread use of mobility credits allied with scrappage or “car surrendering” schemes, such as those recently piloted in Coventry, to get people out of cars and trying alternatives.

  • The recently announced INFUZE project in Leeds involves communities in designing for a future where there is no need to own your own car (as reported in LTT magazine, LTT892, 21 May 2024). Shouldn’t London be trying a similar approach?

  • The proper recognition of the role of shared (zero emission) cars as part of an integrated transport offer and as a way of reducing the need for car ownership (particularly in outer London). Why not launch a proper TfL car club roundel and explore pilots around the possible impact of bringing this offer inside the TfL payments system?

  • A citywide approach to provision of mobility hubs, that develops the alternative to the car into a proper hard-wired opportunity, rather than the rather ad hoc feel they have at the moment (I’m looking at you, rental e-bike discarded on random street corner).


The INFUZE project in Leeds aims to help people adjust to life without car ownership. Could similar pilots work in outer London?

As others have written about elsewhere, fairness has to be a key consideration in bringing people along with professionals on this journey - not an afterthought. That doesn’t mean doing nothing, in the way some people deploy that argument. But it also does mean not covering your ears to legitimate concerns about unintended impacts on those least able to make these changes. Mitigation for more progressive policies in the form of a just transition fund for mobility, or similar evolution of the ULEZ scrappage fund, would be necessary to win widespread public acceptance for this agenda.

4. Make a plan to address Freight and Logistics emissions

Despite making up 15% of vehicle-miles in London, freight vehicles emit a quarter of the total carbon emissions. This is a daunting stat for transport planners who can often struggle to develop effective interventions for an industry as diverse and commercially sensitive as modern logistics. If asked, most industry professionals will point to a clear role in improving last mile efficiencies – via support for cargo bikes, local consolidation centres, progressive kerbside management and the like. These are important - apparently that final stretch can account for half the carbon emissions that can be accredited to a single parcel and obviously, the army of LGVs also causes local congestion and air quality issues.

However, the majority of emissions from freight still come from HGV movements. An astonishing stat is that only around 2% of the GLA emissions from freight arise in central London, with most freight emissions concentrated in outer London - unsurprisingly areas around Heathrow dominate. With longer trip distances out of the centre, the opportunity to move to active modes like cargo bikes is going to be limited. More focus needs to be given to how best to move these vehicles to cleaner electric, perhaps also hydrogen might have a role to play for the heaviest vehicles (particularly if that can be layered on to demand from other sectors such as aviation).

Long before ULEZ was causing excitement in Susan Hall’s household, we had the Low Emission Zone covering the whole of London which did great things in reducing the environmental impact of freight. Could an intervention to toughen standards for that zone for HGVs specifically be possible within the constraints of Sadiq’s manifesto? If not London wide, could clean freight zones be explored for the most intensively used/worst air quality areas to nudge operators to invest in more efficient vehicles? This could be dovetailed with more investment for a new commercial scrappage scheme, or subsidies for onsite infrastructure like rapid chargers etc. These can’t be done overnight, longer timelines would need to be given to provide certainty for businesses, but within a mayoral term it seems doable.


A Clean Freight Zone in the capital could encourage operators to invest in electric HGVs

5. Use new regeneration zones to deliver sustainable transport

The mayor has committed to a more focused approach to housing delivery, stating he will take “decisive action” to create new Land Assembly Zones and set up more Mayoral Development Corporations to boost overall housing supply and drive regeneration.

It’s not a quick fix, but how do we use these areas of intensification to turbo charge transport investment, helping reduce impact of new journeys but also opening up new sustainable transport options for existing communities? This becomes even more important given that greater largesse from the Treasury (even one controlled by a Labour minister) feels rather unlikely for the capital.

A good example here might be around Heathrow. There’s huge opportunities to better plug the airport and surrounding employment and residential areas into local rail network from both the west and the south – creating a proper Western integrated transport hub in zone six of the size necessary to deliver real mode shift, akin to those developed on the rail networks in Berlin and Amsterdam, amongst other cities. There is agreement that the airport and air passengers will chip into that, and significant farebox revenue that can be leveraged to finance borrowing towards the necessary investment capital. But doing these things wholly without recourse to the public purse is difficult, and it seems likely that it might require a diversification of private sector finance such as from property development along the lines we saw to underpin delivery of the Northern line extension to the Battersea Power Station redevelopment. That is likely to need some Mayoral elbow grease to get across the line.

To be fair, the manifesto does make reference to major transport projects serving opportunity areas (notably West London Orbital and the DLR extension to Thamesmead), but the story of rail in London shows a need for a constantly evolving pipeline of such schemes.

Being realistic, these big ticket items are not going to reducing carbon by much in 2030, so there will be a need to have transformational active travel and bus improvements as outriders for the rail kit. That’s why I was supportive of the Mayor’s idea of a bus based Bakerloo line extension as a Phase 0 for that enhancement. The Glider BRT system in Belfast shows what can be done by simply bringing together all best practice around delivering excellent quality bus services into one place and promoting it hard. A similar level of ambition, unlocked and part funded by serious levels of regeneration, could be delivering significant mode shifts before the end of the decade.


It would be nice to plug all these ideas into a waterfall graph and watch the emissions fall pleasingly to zero over the course of the next 2,000 odd days, and thus meet the Mayor’s 2030 target. I’m not sure if they will get us completely across the line, but what we do know is that simply focusing on electrifying the bus fleet, some more active travel infrastructure (which largely targets less polluting shorter trips), and a School Street or two definitely isn’t going to cut it. And whilst more major rail schemes are absolutely needed, and as quickly as possible, they will play little part in achieving the 2030 target given the considerable time needed to get them online.

The window of opportunity for infrastructure schemes to deliver the 2030 target is already small, and is shrinking further by the day. Superloop 2 and similar quick to deliver initiatives have more promise, particularly if coupled with a real push on bus priority in partnership with the boroughs.

But, having ruled out road user charging and tightening ULEZ standards, without bold transport planning and policy interventions along the lines discussed above, that 2030 target is in danger of remaining just that - an aspiration. London has both the need, potential and capacity to show the rest of the country the way to Net Zero. A suitable plan is, however going to be required pretty soon.

References and Links

Mark Frost is Director at Fern Consulting, Policy Director for Transport Planning Society and advisor to London’s Strategic Transport Forum (part of the London Technical Advisors Group of lead borough officers for transport).

This article was first published in LTT magazine, LTT894, 18 June 2024.

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