44. Street smart, understanding our local mixed streets


As cities expand around the world with investment flowing simultaneously into new suburbs and the revitalisation of city centres, the mixed, often arterial, streets that both connect the parts and which, historically, have been the focus of local public amenities – shops, public transport, municipal services, leisure and sports facilities, bars and restaurants, etc. – have come under increasing pressure.  The twin threats of spiralling traffic growth and concentration of amenities and investment in large accessible and easy to develop central or out-of-town locations undoubtedly contribute to these trends, but they may also be a bi-product of neglect amongst local policy makers, businesses and development and management professionals who don’t understand such places and their layers of complexity or know how to manage them.

The result manifests itself in a spiral of decline through which many formally vibrant local commercial streets that were once the social and economic centres of their neighbourhoods, have become degraded by traffic and beset with run down and derelict property, empty sites, ubiquitous signage, fast food establishments, and marginal uses.  These trends are witnessed in major cities across the world.

A case-in-point are UK’s most high profile mixed streets – its high streets.  These have been the subject of much recent discussion and successive policy and regeneration initiatives following a much publicised decline as retail has concentrated into larger centres, or moved out-of-town or on-line.  Typically, however, the focus of such concern has been on just a small fraction of the mixed street stock, namely town centres, and even then on just part of the real estate – the retail.  In recent years a surfeit of high level reports and commissions have focussed on this issue, but most see the problem from this same very limited perspective?

The essential resilience of mixed streets

My own recently published research on local high streets in London revealed that, seen in the round, mixed streets are more resilient and far more significant than may at first seem apparent[1].  Utilising key London-wide data sources the work demonstrates that designated town centres represent less than a quarter of the 500Km of mixed streets in London outside of the Central Activities Zone (CAZ), and as the city’s prime connective tissue weave their way across the capital in and out its formally designated town centres.  In such streets just half of non-domestic stock is given over to retail whilst the remainder is constituted from a complex mix of industrial, leisure, civic and business uses.

Map 02_all named high streets

The research revealed that 10% of Londoners live on or immediately adjacent to such streets and two thirds within a five minute walk, giving them a local significance far beyond any other physical structure in the city.  Furthermore, on or within a 200m strip from these streets are located more jobs and double the number of businesses than in the CAZ, and within 500m is 75% of London’s developable brownfield land. The startling figures reflect a simple fact that mixed streets are not simply a space lined with single story retail, but instead have depth, height and hinterland which has been remarkably adaptable and resilient in the face of change.

Problem or potential?

If the evidence in London is reflective of experience elsewhere, then collectively as complex pieces of physical, social and economic fabric, and as large scale sunk investments in urban infrastructure, mixed streets continue to play a vital strategic and local role in cities across the UK and around the world. Yet, as pieces of ‘old’ and decayed fabric, to policy-makers they may often seem to be more part of the ‘problem of the city’ – congested, polluted, deprived, dilapidated, inefficient, etc. – than part of the solution to urban problems.

As such there is a continuing tension between redevelopment and regeneration agendas in many such spaces whilst significant pressures against choosing to invest either public or private resources in such environments remain formidable, especially when set against the relative ease of developing elsewhere where ownership, construction, conservation, regulatory, design and development challenges are not nearly so complex.

The public sector, it seems, has all too often seen mixed streets in planning terms as simply locations on an abstract retail hierarchy, in transport terms as strategic traffic corridors to the detriment of their other local functions, and in urban management terms, as a low priority. Yet, despite this, my research suggested that local mixed streets continue to command considerable local support from surrounding communities, and encourage sustainable and inclusive patterns of living in the process.  A few pioneering cities around the world, including Melbourne, Berlin, and Auckland are even beginning to explore the potential of their mixed arterial streets as the foci for large-scale city-wide urban growth and densification strategies.

Yet whilst the universal mixed street is sometimes seen as a place of potential to address the twin challenges of urban growth and sustainability, more often it is viewed as an urban problem to be overcome, or is simply ignored.  This is unlikely to change until these spaces are better understood by those with responsibility for their future.

A framework for understanding mixed streets

As perhaps the most complex pieces of urban infrastructure mixed streets are also one of the least researched. They are at one and the same time:

  1. Physical fabric – often historic in origin, degraded but robust in the face of significant change
  2. Places – of social activity and economic exchange
  3. Movement corridors – channels of communication through the city
  4. Real estate – typically in multiple uses and highly fragmented ownerships


Within such a context a significant challenge lies in understanding the needs, conflicts and synergies within let alone between, the four dimensions.

So whilst land uses, including particular types and quantities of retail, will come and go, the challenge is to see mixed streets in a holistic manner, where issues of place and movement are reconciled within the physical fabric in a manner that helps to maintain a viable diverse real estate market, the efficient functioning of space, and that supports vital and safe social space. This implies a view of the city that sees the street itself embedded in a hinterland that feeds and shapes the space whilst the resulting street is continuous and connective (A).  It also opens up the opportunity for the linear street and its hinterland, often continuing over many miles, to become a planning entity in its own right, rather than the sorts of spatially defined and localised notions of neighbourhoods and town centre retail designations that characterise many spatial plans (B).


Only such a holistic understanding of mixed streets as real places will begin to do justice to these hugely complex, yet fundamental and inherently sustainable pieces of the city.

Matthew Carmona

Professor of Planning & Urban Design

Bartlett School of Planning, UCL


August 2014

[1] http://bit.ly/1lWLncX