Triple Access Planning

Discovering the ‘sweet spot’ of Triple Access Planning

Travel is a derived demand. Ah, yes, we often remind ourselves of this – and we seem to manage to derive an awful lot of it by how we plan (take a look at the monstrous Thanksgiving jam in LA of 12+ lanes of bumper-to-bumper vehicles). But, as any good transport planner knows, “it’s about access, stupid”. My aim here is to challenge you to think hard about access and its role in transport planning.

Travel is derived from how we design for access and how people wish to, and are able to, fulfil their access needs. However, here’s the rub: “[a] seemingly simple idea, that goods and services and other activities should be easy to reach, is somehow difficult to implement in practice” (so says Professor Susan Handy from California in her excellent 2020 article ‘Is accessibility an idea whose time has finally come?’). Derek Halden, one of the pioneers of accessibility planning in the UK, I’m sure feels her pain. Susan worries about an intense focus upon accessibility measures that may be getting in the way of addressing access in practice. She advocates for access being employed as a way of thinking. I couldn’t agree more. Stephen Cragg from Transport Scotland has reminded us that we need to be philosophical about transport before we plan it. I would take an old adage and adapt it: failing to think and then plan, is planning to fail.

Thinking about access
So, let’s do some thinking about access that might in turn help to influence transport planning practice. After Professor Phil Goodwin (who said as much for changing travel behaviour), ‘changing access’ is has an important double meaning: how we are able to reach things we need or desire is changing and can be changed (‘changing’ being an adjective or a verb). With ‘changing’ in mind, motorised travel does not necessarily need in future to continue being as dominant as the derivative of society’s pursuit of access.

Look back to 1989 when the World Wide Web was invented, and from that vantage point look forwards over the 30 or so years to present day. The digital age has collided and merged with the motor age. From a 56k modem (56 kilobits per second) in the 1990s, I now have a broadband connection speed at home of up to 100 megabits per second. Speed of data movement is around 1700 times faster – and the digital activities and services of today would have been unrecognisable 30 years ago. Just imagine what digital connectivity could look like in 30 years’ time. Can you?

Access fulfilment was never just about transport. We live in the Triple Access System (TAS), a concept Cody Davidson and I set out in 2016 (see Figure 1). The transport system provides access through physical mobility, the land-use system provides access through spatial proximity, and the telecommunications system provides access through digital connectivity. Stephen Cragg put it to me: “that simple triangle that you and Cody created hits that sweet spot of being easy to understand and oh so powerful in communicating an idea that once it’s there, you can’t believe you’ve never seen it yourself”. But what do you think?

Figure 1. The Triple Access System and adaptation of access in response to the pandemic.

Then along came the pandemic. The societal response to COVID-19 has demonstrated (more powerfully than we could have imagined in 2019) how integral to each of our lives (in different ways) the TAS is. The pandemic has also revealed two key attributes of the TAS: adaptability and resilience. Social inequalities have been further exposed in terms of these attributes and that there is an important distinction between being able to and wanting to do things differently. Nevertheless, society in parts turned from a high dependence on physical (motorised) mobility for access towards much greater dependence upon digital connectivity (for work, education, shopping, socialising), coupled with a greater emphasis on spatial proximity (see Figure 1). Perhaps our highly connected world is to blame in part for the pandemic. But how would we have coped with such a pandemic in 1989 (COVID-89), in an era without the flexibility of access offered today (to some) by the TAS?

What is clear to me is that transport planning cannot ignore the TAS. We are in a period of deep uncertainty about future transport; to help address this, we need to deepen our understanding of the role played by spatial proximity and digital connectivity. “But this is looking very complicated, how are we going to measure and model all of this?” some of you may be thinking. My response is to offer a reminder that a model is a simplification of reality (and that models come in different forms) and also to stress that it is better to be approximately right than precisely wrong. We should see the TAS as helping us think differently about how we make sense of future mobility and how we plan for it.

Systems thinking is a form of modelling – specifically the use of causal loop diagrams (CLDs). Creation of such diagrams helps us to understand a system’s dynamics in terms of the variables involved. This can be done for each of the TAS sub-systems (see for example Figure 2). It is then possible to see how reinforcing and balancing effects can be created within and between the sub-systems. It reminds us, for example, how reinforcement of a cycle of growing dependence on physical (motorised) mobility for access has come about.

Figure 2. Systems thinking – a causal loop diagram depicting variables and dynamics in the transport system.

But it can also help us appreciate how countervailing (balancing) effects can come, or be brought, into play. Consider for instance a (re)balancing away from motorised mobility (involving dynamics across the three TAS sub-systems):

  • Normalisation of digitally accessed activities and services could arise (telecommunications system).
  • This could reduce demand for distant face-to-face activities and services, in turn reducing the demand for motorised mobility, then reducing the policy priority for access based upon motorised mobility (transport system).
  • This could make way for continued or heightened policy priority for access based upon active travel, leading to improved availability and demand for proximate face-to-face activities and services (land-use system).
  • Such dynamics between the systems would foster ‘live local, act global’ accessibility in this scenario. The scenario is not a million miles away, for some people, from what has been occurring during the pandemic.

Triple Access Planning
Just as transport planning has the present and future of the transport system in mind, Triple Access Planning (TAP) has the TAS in mind. Am I suggesting that transport planning should make way for TAP? Yes and no. We may still see ourselves as transport planners but we should think about and apply our approach to addressing the future of the transport system through the lens of the TAS. Here is my definition of TAP:
The tripartite consideration of fulfilment of society’s access needs in pursuance of social, environmental and economic outcomes, in which actions are cognisant of and seek to influence the inter-related mechanisms of physical mobility, spatial proximity and digital connectivity.

TAP is outcomes-oriented and therefore vision-led. Actions taken (policy interventions) might be confined, in the case of transport planning and policy, to influencing physical mobility. Nevertheless, these actions should at least take account of influences from, and upon, changing spatial proximity and digital connectivity. Preferably, a more joined up approach would be taken in which actions across all three sub-systems are identified in a co-ordinated way to bring about mutually reinforcing effects to realise economic, environmental and social outcomes.

In the forecast-led paradigm of predict and provide, application of TAP could get caught up in the question “how is it possible to fully understand and model the TAS to forecast what its future supply and demand will most likely be (for do-nothing and do-something cases)?” (see above). However, I have always seen the concept of TAP as instead being integral to the vision-led paradigm of decide and provide (see Figure 3).

Demand-led supply – ReactiveSupply-led demand – Proactive
Predict and provide – forecast a most likely mobility future (within sensitivity-tested bounds of uncertainty) and provide a means to accommodate projected demandDecide and provide – decide on a preferred accessibility future (and outcomes) and provide a means to move towards it in a way that accommodates the deep uncertainty ahead
Figure 3. Alternative ‘transport’ planning paradigms.

So, what might characterise a preferred accessibility future? A good illustration comes from combining three different sources of recent inspiration into an imagined whole: (i) Scotland’s National Transport Strategy Delivery Plan has an intention to “develop a coordinated package of policy interventions to reduce car kilometres by 20% by 2030 [compared to pre-pandemic]” (physical mobility); (ii) Anne Hidalgo made the 15-minute city a centrepiece of her successful 2020 re-election campaign as mayor of Paris (spatial proximity); and (iii) the Welsh Government “has stated its long-term ambition to see around 30% of Welsh workers working from home or near from home” (digital connectivity). Could such triple-access thinking be brought into practice now?

Getting set for TAP
I believe there are five key reasons why the time is ripe for TAP:

  1. The strong imperative – we face a climate emergency and a legal obligation in the UK to decarbonise which means a form of triple-access is needed that treads more lightly on the planet.
  2. The sufficiently compelling offer – digital connectivity has rapidly matured, and will continue to develop significantly, as the third-leg of the accessibility stool.
  3. The harness – a chance to better embrace access by treating it as a way of thinking in planning (coupled with simple measurement and modelling).
  4. The psyche – an awareness, rethinking and reapplication of accessibility thrust into many personal and professional lives by COVID-19.
  5. The application – it forms a natural part of the decide and provide paradigm that is diffusing into transport planning.

Building upon the use of systems thinking, TAP involves exploring plausible future TAS configurations – i.e. scenarios – according to the critical uncertainties of society’s relative/absolute change in preference for and consumption of physical mobility, spatial proximity and digital connectivity (see Figure 4). Together such scenarios reflect uncertainty over a ‘do nothing’ future because the ‘triple access policymaker’ cannot have full control over shaping the future – some system change (involving multiple other actors) will be out of their hands.

Figure 4. Alternative accessibility features.

By then having in mind a preferred accessibility future, ‘do something’ policy interventions can be designed and tested to determine their resilience in being able to help progress towards the preferred future in the face of this uncertainty.

Are you still with me or did I lose you?! It must be said that TAP is not necessarily about making (strategic) transport planning any easier but it is about improving its fitness for purpose.

Triple Access Planning for Uncertain Futures
I’m delighted to say that I have the privilege of co-ordinating the new pan-European three-year project called ‘Triple Access Planning for Uncertain Futuresx’ to explore all of this further, starting formally in May 2021 (Figure 5 shows the project logo). The project aims to advance guidance to improve the resilience and adaptability of Sustainable Urban Mobility Plans (SUMPs) in the face of uncertainty. A European concept, SUMPs represent a shift from being forecast-led to vision-led in terms of planning, with greater emphasis on outcomes (beyond accommodating traffic) and a recognition that shaping the future should be a participatory process (reflective of a diverse society).

The project is research-based and practice-oriented involving academic, city authority, national transport authority and consultancy partners in Italy, the Netherlands, Slovenia, Sweden and the UK. Its approach involves four phases: (i) theory – deepening systems thinking regarding triple access, developing and exploring plausible accessibility scenarios, and identifying triple-access measures; (ii) practice – critically examining existing urban mobility plans and the guidance they have followed, and engaging with plan developers; (iii) design – examining the existing knowledge base and wider pool of practitioner and expert insight to then draft a TAP for uncertain futures handbook; and (iv) application – applying the handbook across seven case study cities to review and rework their urban mobility planning approaches and evaluate the contribution to urban mobility planning of the new handbook’s guidance.

What times we live in! Transport and society are in a state of flux. How we plan for the future of transport is in a state of flux. As you are hopefully aware, the revised competencies for the Transport Planning Professional, launched in March 2021, give greater emphasis to uncertainty and a need to bring constructive challenge into our behaviours as professionals. With that in mind, I extend a warm invitation to other transport planners to critically reflect upon this proposition for triple access planning. We’d love to hear from you.

Glenn Lyons is the Mott MacDonald professor of future mobility at UWE Bristol, and the coordinator for the project Triple Access Planning for Uncertain Futures.


This article has previously been published in Local Transport Today.
Lyons, G. (2021). Discovering ‘the sweet spot’. Local Transport Today, 823, 17 May, 16-17.

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