Overcoming physical barriers roundtable

Major roads, railways, waterways and other infrastructure are integral for connectivity, but ironically risk causing local severance, dividing and cutting off communities. Attempts to overcome these physical barriers often come up against other barriers, such as cross-border and multi-stakeholder working, access to finance and limited data.

On 19 July, in the first of two roundtables as part of our Overcoming Barriers project, cross-sector senior practitioners shared experiences of tackling physical barriers. The event was kindly hosted by project sponsors Arup.

A Chatham House summary of the discussion and list of participants is below.

physical barriers roundtable discussion
Participants chat over breakfast ahead of the discussion

Understanding and quantifying impacts of physical barriers

Everyone has experienced disconnected places in London, but the social, economic and environmental impacts are not well quantified. For example, there is no central, accessible map of London’s physical barriers. Underlying this, ‘unseen’ barriers of underground utilities and services can stymie delivery and are expensive to map, though emerging initiatives like Project Iceberg may help.

Through analysis such as Space Syntax’s integrated urban modelling, it’s possible to measure the impacts of physical barriers on movement, health and access to services. Less is known about how people actually perceive barriers. For example, in one London town centre – featuring a major strategic road and two railway stations – consultations with residents surprisingly found they see the road as a much more significant barrier than the railway lines. This in-depth engagement with local people helped gain support for a significant intervention that would cause a lot of disruption during construction.

There’s also a temporal dimension. Over time, routes may ‘wither’ due to underuse, while neighbourhoods and socioeconomic profiles change. This is nearly impossible to quantify but important to understand: efforts to integrate disconnected neighbourhoods not only need to overcome physical barriers but lifetimes of psychological barriers.

Finally, the financial impact of physical barriers – and removing or reducing them ­– is not well-known in the London context, making it difficult to prove return on investment to developers and investors.1

Challenges to addressing physical barriers

Policies and regulations

Just as there’s no central repository of London’s physical barriers, neither is there a city-wide strategy to understand and address barriers and their impacts. Individual borough and GLA policies may differ, even where they share responsibility for pieces of severing infrastructure. At street or building level, building regulations only supply guidance for current needs, failing to account for our future, ageing population. Some developers go above and beyond, but many only meet the most basic accessibility requirements and are unlikely to make any additional effort without financial incentive.

Compounded barriers

New development is occasionally guilty of adding barriers, sometimes even while trying to overcome others. For example, Crossrail’s route through Newham brings greater connectivity to the rest of London – along with a mile-long concrete wall intended as a noise, flood and trespassing barrier.

Politics and priorities

Several participants had experienced backlash against schemes that offer significant relief from physical severance but reduced affordable housing provision. Some reported planning applications stalled by elected members with more concern for car parking spaces than the quality of the environment and overall community benefit. Meanwhile, many developers focus on short-term profit rather than nurturing connections beyond a project’s ‘red line’ boundary – and holding out for longer-term gains.

Time and resources

Local authorities have the power to demand better integration – if they have the personnel to devote to it. For example, transport planning teams can review planning applications, comment on aspects related to movement and accessibility, and seek to influence planning decisions. In reality, they and other departments are stretched for resource with little time to review applications beyond the bare minimum required.

Money and value

Even the smallest schemes, such as lighting improvements, require funding which is increasingly hard to come by. Larger schemes with multiple stakeholders are especially challenging, as financing mechanisms tend to cater for less complex projects that can deliver outcomes on short timescales. Mechanisms like CIL could help, but aren’t paid until development is complete. And, as noted earlier, lack of financial data means it’s difficult to show return on investment.

Good quality public realm can mitigate the impacts of infrastructure, providing improved routes and opportunities for communities to come together. A placemaking approach will also create value for developers in the long term. However, the priority for many volume housebuilders is to sell units quickly; there is – as yet – no incentive to do things differently.

 Recommendations & approaches


  • Understand and communicate the financial benefits of addressing severance to developers and investors
  • Communicate benefits and trade-offs of development to members and residents

Planning and guidance

  • Reflect on schemes that don’t receive public approval – and be willing to adapt or start fresh
  • Make better use of leftover land by barriers (e.g. roadsides, areas along railways) as green space or to improve connections, especially where publicly owned
  • Use the planning process to ensure schemes address barriers and extend development benefits beyond red-line boundaries
  • Carry out post-completion consultations to discover lessons learned and outstanding issues for a development (e.g. ongoing difficulties crossing a nearby road), which can be addressed in adjacent development sites
  • Create accessibility accreditation (like BREEAM and WELL Standards) to incentivise developers to deliver more than minimum requirements


  • Secure small pots of funding for small-scale barrier reduction or removal, which can improve connectivity, act as a showcase/pilot and attract more funding for larger-scale works
  • Where possible, borrow against future CIL contributions to bring schemes to remove/reduce barriers forward

Reframing barriers

Even with the most effective guidance and funding, the reality is that most of London’s biggest barrier-causing infrastructure isn’t going away. With no option to remove these barriers, reframing them is one way of addressing their negative impacts. At a neighbourhood-wide scale, organisations like the Westway Trust and Peckham Coal Line are transforming severing infrastructure into community assets. These organisations also offer insight into how community groups and trusts could take the lead on overcoming barriers, which could be replicated across London.

Newham trackside wall
Newham Trackside wall is a byproduct of Crossrail. To reduce its negative impact on the public realm, Crossrail has commissioned local artists to design murals with residents, ‘reframing’ the wall as a public art canvas and bringing people together in the process. Photo from Crossrail.


Paul Augarde,Director of Placemaking, Poplar HARCA
Mark Baigent, Interim Director for Housing, Regeneration & Sustainability, LB Tower Hamlets
Dr Tom Bolton, Researcher, Writer & Design Panel Manager, Frame Projects
Paul Creed, Head of Development & Placemaking, GLA (Royal Docks)
Gareth James, Senior Transport Projects Officer, LB Hounslow
Jessie Lea, Senior Programme Manager, LB Lewisham
Mei-Yee Man Oram, Co-Leader, Accessible Environments, Arup
Nicola Mathers, Head of Leadership, Future of London
Tristan McDonnell, Director, Arup
Ed Parham, Director, Space Syntax
Tricia Patel, Senior Equity Partner, Pollard Thomas Edwards
Amanda Robinson, Head of Knowledge, Future of London
Alex Russell, Joint Chief Executive, Westway Trust
Janet Townsend, Director of Development, LLDC
Nick Watson, Director, Places for People


[1] Some work exists for major roads. See UCL’s Street Mobility Toolkit and other research by Dr Paulo Anciaes, and this archived DfT summary of how various countries monetise road-induced severance.