How much road is too much: where's your double yellow line?
To focus on tech over people is to risk repeating old mistakes.
In November last year, London Centric published Chris Marshall’s remarkable map of the motorway network once planned to slice through London. A vast gyratory over Clapham Junction. Flyovers through Chelsea and Camden. It’s hard to imagine now that there was, at one point in the city’s still recent history, genuine support for the wholesale demolition of homes and historic buildings to make way for the motorway.
Thankfully, with local resistance and a change in political climate, those plans were scrapped before the bulldozers arrived (save for a few stray bits of flyover to nowhere).
And yet, the private car still shapes our cities. Not only through these major arteries, but in the everyday geography of our streets. In London, on-street parking takes up as much space as 10 Hyde Parks. More than half of the UK’s front gardens have been paved over. The balance between movement, space and safety hasn’t ever been fully resolved to everyone’s satisfaction – perhaps that’s impossible.
“Designing a dream city is easy; rebuilding a living one takes imagination.”
- Jane Jacobs
Urban transport debates are not primarily technical problems about traffic flow, but social and political questions shaped by identity, values and perception.
At an individual level, where do you draw your own red (or double yellow) line when it comes to the allocation of space for private cars: would you accept a smaller local park to widen a congested road? Or would you rather see the road closed to traffic altogether? And to what extent do you feel your choice identifies you with a political ideology – and does that make it harder or easier to change your mind?
Identity is just one driver of behaviour
People hold a spectrum of views about what motorists are ‘entitled’ to, which can’t be understood through traffic counts alone - and doesn’t always appear logical. Behavioural research helps reveal why people choose to drive, cycle or walk and how factors like habit, perceived safety, social identity and fairness shape those choices.
Dr Lara Suraci, Behavioural Scientist at DG Cities is part of the team using behavioural systems mapping (BSM) to get to the heart of the systems driving behaviours. “We can use BSM to explore these relationships because they show how individual motivations (convenience, autonomy, safety) interact with wider structural factors (road design, public transport quality, cultural norms).”
Mapping these behavioural dynamics across a city can highlight where tensions or opportunities cluster. It also says something about the value of pilots, which can sometimes be seen as an unnecessary public expense. A local survey or micro-scale experiment such as a temporary road closure or reallocated parking bay can reveal how attitudes shift when people experience change first-hand. It moves the conversation from abstract policy to lived reality.
Transport for London’s data from Low Traffic Neighbourhoods on modal share illustrate the value of evidence: post-implementation studies published in 2024 show a net reduction in traffic across wider areas, no measurable impact on emergency response times and higher rates of active travel – countering the messages shared by campaigners. Yet perception often diverges from reality, shaped by emotion, ideology and choreographed by media framing.
Local conversations influenced by a global narrative
That divergence is amplified by national and global framing of culture war flashpoints. LTNs or congestion charges become shorthand for the ‘war on motorists’. Cycling infrastructure gets labelled elitist, even though it’s one of the cheapest, most accessible means of mobility. The nuance of local design decisions for local needs can quickly be lost in viral outrage.
Returning to the point on political affinities, social media accelerates this polarisation, turning planning into a performance of identity politics. Studies of online discourse around LTNs show how automated accounts and coordinated campaigns can skew perception, with a handful of highly active users generating the majority of anti-policy content. Against this backdrop, evidence and empathy must work hand-in-hand.
Data helps clarify what’s true, empathy helps people hear it.
That combination matters even more as we enter the next major shift in urban mobility. Just as planners in the 1960s looked ahead to a car-dominated future, we are now at another inflection point. The UK’s Automated Vehicles Act will allow self-driving cars on the road as early as 2026, with some operators already announcing services. The debate about control, freedom and responsibility is set to shift again, this time from human drivers to algorithms.
This raises a new set of questions. It’s no longer only about how we share road space, but who (or what) uses it. If agreeing on LTNs proved difficult, navigating the ethics of machine-led mobility will be more complex still. Bias, fairness and accountability become design problems, not just policy ones. That’s why much of our research, including projects like Ethical Roads, has explored how and where human values guide these decisions.
“Technology is agnostic – it’s an enabler. The ethical and societal risks come with the powers that use it for their purposes. So, technologists, politicians, city planners should see themselves as designers with public good, at its broadest and for those disadvantaged, always the target outcome.” - Ed Houghton, Director of Research & Insights
Technological innovations often align strongly with some values while challenging others. Self-driving vehicles promise societal benefits like improved safety and reduced congestion, thanks to connected systems that support better decision-making. But autonomy can also conflict with values around human welfare, affecting the job security of professional drivers or reducing everyday social interactions. As Emily King noted in ‘technological innovation with human values’, innovations that overlook these dimensions risk drifting away from widely held principles of benevolence and universalism.
Unless cities consciously prioritise human experience over technology, they risk repeating past mistakes of designing around cars rather than people. This time through autonomous vehicles instead of motorways. “Public engagement has to be at the heart of new services so that it’s people that will ultimately benefit from their potential for improved safety and accessibility,” adds Ed Houghton. “That’s why our public research workshops across the UK are so important.”
Autonomous vehicles are a current example, but the underlying question is broader: do we measure progress in terms of cars or in terms of streets? It shouldn’t be a binary choice. But if we design systems that prioritise machines over human experience, we may find ourselves repeating the very mistakes that London narrowly avoided half a century ago.
DG Cities is a London-based innovation company: dgcities.com