Air Questionable Plan

 

The Government’s recently released consultation draft Air Quality Plan is more of an Air Questionable Plan. Why? I may be down to one blog a month these days, but this is a question I’m keen to answer.

It is often written that people struggle with environmental risks, because they are not imminent, proximate, and/or visible. That’s why people may feel climate change is an important issue to address, but struggle to be motivated. Air pollution is more local, but it’s potential, personal, health impacts may be even longer-term than the climactic increase in floods and droughts.

So it was easy for the Government to drag its proverbial heels until environmental groups forced its hand through the courts. Then they published a consultation Plan. Which I read. And, with my fairly extensive knowledge of local transport and my less extensive, but still greater than average awareness of air pollution, realised the Government was still dragging its heels. And its exhaust pipes.

Local air pollution is not a new problem. When I worked in local government, we were measuring, monitoring, and making plans to mitigate a decade ago. We even wrote a business case to introduce a Low Emission Zone. One that charged certain polluting vehicle types, but also invested in walking, cycling, and public transport. One not dissimilar to what the Government calls in its consultation document a ‘charging’ Clean Air Zone. But in 2010, as the Conservatives came to power, our business case was pulled. We continued with plans to improve sustainable transport, but we were not encouraged to resubmit any charging measures in the new rounds of challenge funding. Charging was part of the war on the motorist (including freight) that the new Government strove to roll back.

Fast-forward seven years, and it looks like anything too anti-motorist will still be discouraged. Or at least framed to ensure that possible political fall-out is local, not national. Charging is only to be implemented as a last resort. Somehow local authorities are supposed to encourage and support the mass retro-fit of polluting vehicles instead if at all possible. Or engineer their replacement with cleaner models. Even if many of the fleets in question are privately owned and operated. Local governments are also going to have to either use their own shrinking resources or compete for funding, spending money building business cases before they win, or don’t win, a penny.

In building the business case for Clean Air Zone measures, local authorities will also be aware that the Government’s guidance takes a very minimalist approach to the role of increasing the share of other modes like walking and cycling in improving air quality. It lumps all the alternative modes together as one measure in its list of eight , whilst four bullet points are given over to ways to reduce vehicle emissions without reducing vehicles. One of these four is: “Improving road layouts and junctions to optimise traffic flow, for example by considering removal of road humps”, a measure that is repeated as the first suggestion in a paragraph on “targeted infrastructure investment”.  What signal does this send? The safety of pedestrians and cyclists is secondary to improving the flow of traffic, despite traffic being the source of the pollution?

Furthermore, there is no mention anywhere that air pollution is measured as much by the population breathing it in as by the absolute amounts of pollutant present. That’s why so little of the strategic road network – less than 1% – is affected. There aren’t many schools and hospitals with motorway frontage. So why is there no mention of removing traffic entirely outside such sensitive receptors? Why not more pedestrianisation or “filtered permeability” with physically blocked streets to prevent through traffic?

I’m not saying that I have all the answers. And even this consultation document admits charging might be necessary. But neither do I think I’m jumping to conclusions to suggest that the draft Air Quality Plan favours the motorist over anyone who gets around in a different way, and pushes responsibility onto local governments, especially all those polluted, urban ones, many of a redder political persuasion. It makes it the whole commitment to reducing air pollution look rather… Questionable.

 

Road Rage at the Red Sea

Happy Passover, blog readers!

Have you ever wondered how the Hebrews crossed the Red Sea? The simple answer is on dry land, created by G-d’s miracle through Moses the prophet. But does that really explain anything?

Let’s picture the scene in more detail. The Hebrews, and we’re told they were numerous, have fled Egypt with their families, old and young, as many possessions and as much food as they could gather together at speed. There were probably some animals, maybe even carts, or perhaps wheelbarrows. They have come to the edge of the Red Sea and run out of land, never mind road. Do they queue up in an orderly line awaiting Moses’ miracle to enable them to cross? Unlikely.

In all probability, they were a milling mess, spreading out along the shore in both directions, in some areas crowded many bodies deep, in some areas standing solitary to peer out across the waves in the hope of spotting this promised land. So what happens when they hear the chariots of the Egyptian Army behind them and Moses raises his staff? Do they then re-group, line up with military precision? Unlikely again.

So how did they cross the Red Sea? Perhaps Moses created a bridge of dry land big enough for them all to walk abreast, but that’s certainly not how it’s shown in the paintings. Sure they were probably fine once between the towers of water on dry seabed. But before that? I imagine they were a seething, pushing, elbows-out, road-rage-driven, traffic jam. If you didn’t try to run round the edges and push ahead, then everyone probably cut in front of you, leaving the Egyptian warhorses nipping at your heels.

Or at least that’s the image that came to me last week as we sat queuing to get into the tunnel to Logan Airport in Boston, my aunt coming ever closer to missing her flight. Tunnels and bridges are often pinch-points, but in this case, behaviour played a part too. As if there were ancient, avenging Egyptians at their heels, car after car cut down the inside lane headed towards South Boston and then cut in at the last minute, pushing those waiting outside the tunnel ever further back in the queue, stationary and sweating.

And so, eventually, we had to do the same. With guilty conscience, we cut around, half wishing we’d done it earlier, half wishing we weren’t driven to being another of ‘those bastards’ as other drivers were probably swearing. My aunt had the barest half hour until her flight took off, and by the time she reached the gate, her ticket had been sold. She just managed to secure another empty seat at the back of the plane. Luckily it wasn’t oversold like the plane that made the news this week.

Yet it does make you wonder. Not only at the insanity of the design of the tunnels that access Logan Airport or the parallels that could be drawn between Boston’s peninsular, landfill airfields and the mooted Thames Estuary island airport, which would be likely even less accessible to the volumes of people it needs to serve. Nor necessarily solely at the challenges of modern driving with the limitations of GPS and traffic updates, which you expect will enable foresight and contingency planning, but often get you within a few miles of your destination, reporting a problem only when you are immovably stuck in it. No, it also makes you wonder at that ancient challenge, crossing the Red Sea, G-d’s people already risking G-d’s wrath with their own road rage long before the Golden Calf episode. Seems to me agetting across bodies of water was probably a problem even back then.

Anecdote or Endgame

When I tell friends, family, other mums at the school gate that I’m doing a PhD, they all ask me what my research is about. I’ve been working on my answer:

I’m looking at ‘big data’ to see what it can tell us about risks to how and whether people travel for work during severe weather events. That’s the one sentence version.

Sometimes it’s better to frame it as a question: What do commuters do when a big storm disrupts their usual journey to work, is telecommuting a preferred option, and what does that mean for how we plan for the more frequently extreme weather likely in the future?

That last bit is the aim, the purpose, the endgame of my research and why I believe a research council has agreed to fund it. I’m looking for evidence that might suggest that governments, businesses, and communities change the way they plan for and invest in resilience to severe weather and its impacts on infrastructure and property. And I’m looking in the new world of ‘big data’ because that evidence needs to be as statistically significant and scalable as possible, not just anecdotal.

Well, I’m still chasing the really ‘big’ data, but I have recently acquired some data on the transport impacts of Storm Doris on Thursday, 23 February 2017 in the Reading urban area. Trees fallen down, billboards blocking roads. Trains and buses delayed, diverted and cancelled. My data is sourced from local news reports, Twitter, and passenger numbers from Reading Buses on the day and on a more ‘average’ Thursday for comparison.

A few quick calculations and the results were suggestive. Passenger numbers were down during Storm Doris. Routes affected by diversions and delays due to fallen trees or other debris saw lower ridership than the ‘average’ day, but then so did other routes without noted storm-related problems. Did people stay home? Travel virtually or cancel their activity entirely? Were there map-able patterns?

I noticed that there were some routes which gained passengers. Why were more Vodafone employees on their dedicated services? The numbers couldn’t tell me. Why were more people on the long-distance route to Wokingham and Bracknell and on the Park & Ride service in that direction? A likely answer is that as the trains were even more affected than the buses, some people may have decided to switch. In which case, thinking of my endgame, perhaps Reading Buses should build that likelihood into their emergency planning for that route, run more buses. But was there enough evidence of actual cause and effect, of probability of recurrent behaviour to justify such an operational response?

I’ve been thinking about how much more evidence I might tease out from public data sources or a little more data from the bus operator. Are there patterns in the individual bus trips where the loss or gain of passengers was particularly noteworthy or could be matched to service disruptions? Is it worth looking at the type of tickets, the stops along the routes to get an idea of the demographics of who did or didn’t take the bus? Did anyone tweet their intentions to switch modes, to stay at home?

Yet with every dive deeper into the data, the falling probability of demonstrating statistical significance echoes ever louder. The passenger dataset was less than 90,000 on the average Thursday, falling by over 4%. The numbers on individual routes, different ticket types, different times, quickly descended into the hundreds or tens, even on the popular routes. My recently refreshed, but untested and uncertain statistical skills are already struggling with how to make a more than anecdotal comparison between one average Thursday and one disrupted Thursday during one storm in one urban area. How do I show that the most basic null hypothesis – that the storm had no impact on passenger numbers – is extremely unlikely, never mind look at any route in more depth to propose emergency service tweaks to the operator?

I have to face it. It will always be an anecdote. But it could still be an anecdote with an endgame.

Visions: the potential in probabilities

On 28 February, the RTPI / TPS Transport Planning Network, with CILT and DAC Beechcroft, hosted an event to discuss the RAND Corporation report ‘Travel in Britain 2035’.

The report offers three alternative visions of the future of mobility, which are intended to cover the spectrum of probability, rather than a forecast of reality. One of the authors, Charlene Rohr, explained to the assembled professionals that the aim of their project was to review how emerging technologies might influence our transport systems, and envision the multiple potential futures that could occur.

Why carry out this research? The one certainty in this crystal ball gazing is that technologies affecting transport, which have been relatively stable for decades, are now undergoing significant change. This could transform not only how we travel, but also our lifestyles, and even societies. Imagining visions of the future can help us prepare for them.

It is not only the giants of the Tech world that realise this. Did you see Ford’s Superbowl ad? The car company is promoting a vision of mobility for the future where it would be selling a lot more than just cars – perhaps shifting towards mobility as a service. It seems that car manufacturers will have to offer different models of ownership, operation and efficiency to stay in the transport game.

Transport planners have to change their tactics too. Cost benefit analyses for infrastructure investment currently calculate 60 years into the future – but technology is changing so quickly that making predictions for 2035 is challenging enough. Transport appraisal has never been much good at distributional analysis – considering how investment choices impact upon different parts of society – but if we want to avoid the report’s dystopian vision of a ‘Digital Divide’, then we need to correct that fault quickly. More investment will also be needed in adaptable infrastructure, which avoids locking us into 60 years of technology or behaviour that will be obsolete in 20.

Meanwhile, a lot of the visioning buzz is around fully autonomous vehicles (AVs), which will probably be electric and shared as well. The report’s ‘Driving Ahead’ scenario focuses on this technology, whilst the UK Government is investing heavily to be a world leader in AV development. The Transport Systems Catapult offers some thoughts on this future, summarising the many benefits of going driver-less.

However, as the discussion ranged at the event, it is clear that it is not only the difficulty of transition that may threaten a driver-less society. Land use planners face a capacity conundrum. If AVs result in much less parking adjacent to homes and commercial uses, what should that land be used for instead? WSP|PB had a panellist at the event to discuss some of the answers they’ve envisioned. But the vehicles themselves still need to be off-road some of the time, for storage and maintenance. Where is that going to happen? How do streets need to be re-configured for picking up and dropping off instead of parking? If the reduced travel cost and additional productive time offered by AVs attract more use than the additional road capacity their efficient movement frees up, is the answer to build more road infrastructure?

The RAND report specifically ignores the need for new infrastructure. But even roads aside, all the scenarios require more electricity and ICT infrastructure, built to be as resilient as possible in the face of frequent severe weather and other disruptions.

Yet it is not all doom and gloom. Freight drivers may not be out of a job if the complicated work at either end of the journey becomes ever more involved with shared loading and consolidated delivery. Children may be able to play on the streets again as space is freed from parking and AVs are trusted with their safety. And if policy makers, planners, and transport practitioners are proactive about standards, regulations, taxation and investment, we can push the future to better resemble the RAND report’s more utopian ‘Live Local’ vision, where road user charging replaces fuel duty and mobility is not only a service, but an equitable one.

 

Birthday for the Trees

 

Last week I observed a little-known, but very special, Jewish Holiday called Tu B’Shvat.

I explain it to my five-year-old as ‘the birthday of the trees’, which is a basic, but not inaccurate way of explaining it to adults too. Although it is not listed in the Bible as a holiday, the Bible does prescribe that fruit from trees less than three years old should not be eaten and the fruit brought to the ancient temple should be from trees in their fourth year. So trees needed a ‘birthday’ from which to calculate their age, that would broadly relate to when they had been planted, presumably in the Mediterranean Spring. In the Rabbinic writings known as the Talmud, the 15th of the Hebrew month of Shvat, or Tu B’Shvat was identified as that ‘birthday’ or the New Year of the Trees.

On Tu B’Shvat, it is traditional to plant trees and this tradition has greatly contributed to the greening of the Israeli landscape, where whole forests have been planted in land once largely desolate and desertified. We too planted trees last week, although a snowy, muddy, English woodland in February doesn’t feel much like a New Year for trees and Spring seemed a rather distant promise.

Yet Spring will be in full bloom when the next tree event I’m aware of comes around: Trees, People and the Built Environment, a conference in early April. Unfortunately, I cannot attend, but simply reading the programme was to be reminded and inspired by the ways that trees touch our lives, even in urban areas. We all know that trees make an enormous contribution to the global and local environment, that if you live on a tree-lined street, you are likely to be healthier, wealthier and perhaps even wiser. I grew up on a tree-lined street, making me one of the fortunate ones, and I feel blessed for it.

There were gaps in the row of trees, however, including in front of my childhood home when my parents moved there, the year before I was born. So they filled that gap, planting two maple trees to mark the birth of each of their daughters. By the time I left home at 18, my tree was over twice my height. Now it is much taller again, and I can still appreciate it if I visit my hometown. Without trespassing. Because my parents planted it not in the garden, but on the grass verge, between pavement and street.

Trees and streets and planning can be a trio in a messy relationship. Trees make a street more desirable at the same time as their roots crack the pavement and their falling leaves block the gutters and drains each Autumn. People fight against a favourite tree being felled in a public space, but protest Tree Preservation Orders that protect a tree blocking their planned, new extension.

The problem is perhaps that town and transport planning often operate on a tree by tree or street by street or development by development basis. There is inadequate consideration of strategic tree policies for urban areas. And it is inadequacies like this that the Trees, People and the Built Environment conference aim to address. Perhaps, like the holiday of Tu B’Shvat creates a holistic policy for marking the age of trees, so planners and transport planners can learn to create holistic policies for the presence of trees in the built environment once they have evidence for what they have always known – that trees make for better places.

The Daily March

I was feeling guilty and proud over the last couple days. Guilty that I hadn’t marched, didn’t check and hadn’t even realised that sister marches were organised in British cities until too late. And proud that so many of my family and friends in the United States did march in big cities and small towns around the country.

I’ve slightly assuaged the guilt by writing to my senator, as per the first action suggested by the #WomensMarch movement. And I’ve had a thought that has helped me regain my own sense of pride on this issue. Namely, that I march almost every day.

Or rather, I walk almost every day, and although I’ve written in the past about many of the benefits of walking, I’m not sure I’ve written that those benefits include social justice, community cohesion and generally making a place and its people more civilised.

Because when you walk, you connect to your community. You say hello to people you see regularly, even if they are not part of your social circle. If you live in a diverse community, people with different faces become familiar. People with different views become familiar.

I live in a very split area in terms of the Brexit vote – Bracknell Forest district went slightly to Leave, but it was closer even than the national results. I thought that the reason I find those who voted Leave more understandable than those who voted for Trump, even if I disagree with both, was because perhaps Leave has more persuasive and less extreme arguments. Now I wonder if the reason I understand them is simply because I know them. I know Leave voters in my neighbourhood because I’ve walked around and been in conversations with them.

Mind you, I may never see how Trump as an individual could be seen as anything but repulsive and unrepresentative of the people who voted him in. Yet the real reason I can’t understand why those individuals did what they did is because I don’t know them walking down the street. I don’t live in the United States and unsurprisingly know no one who voted for Trump personally. Yet the state where I am registered to vote, New Hampshire, is as divided as Bracknell Forest and went to Hillary Clinton by the narrowest of margins.

So if I still lived there, presumably walking would have resulted in expanding my horizons and theirs. And even if no one ever changed their minds by such encounters, being on foot and able to see and interact with people around you would still be a way to break through those ominous social media bubbles, put faces to views and improve familiarity with the ‘other’ until perhaps they weren’t so ‘other’ anymore.

Thus, it is important to realise that walking is not only good for your health, your wallet and the environment. It is also good for solidarity, not only on marches with people you agree with, but around your neighbourhood with people you don’t. If we can walk together, we can work together to fight the politics of fear and division, no matter who is peddling them in the future.

 

Infographic-tastic

 

Early in December, I wrote a blog about big data in the abstract. I had just been to a workshop on the topic, which defined big data as datasets that are uncomfortably large for a single machine to process into information. In my blog, I wondered whether actually big data should be defined as datasets that are uncomfortably large for a single human to conceive of and then to trust when they are processed into information.

Now, I have just returned from another workshop where we were taught one way we can make people more comfortable with the information we may derive from our big data research: by presenting it visually in a compelling, creative and coherent manner. A picture is worth a thousand words. Or an infographic should be.

Again, we started the workshop with a definition. Infographics “are graphic, visual representations of information, data or knowledge intended to present information quickly and clearly,” says Wikipedia. Infographics can help explain things, especially patterns, trends or changes over time or within complex systems or geographies. Ideally, they should represent ideas, facts and statistics without distorting them. They should teach, warn, and persuade whoever is the target audience.

They are not new. They can be found in 19th century policy documents, early social science textbooks, every publication of census information for general consumption. More recently, as websites seek to increase content to increase clicks, infographics have proliferated. Their quality has not kept pace with their quantity, although great examples can be found with a little digging. Many at the workshop shared a few favourites, and in the past I have tweeted ones that stir my imagination when I have come across them.

Still, as we turned to more practical exercises at the workshop, we soon learned why there are so many terrible infographics out there. Because whilst a picture may be worth a thousand words, it takes at least as long if not longer to create said picture than to write the thousand words. So it would appear that such an investment of time (and skill, and having decent tools) is not granted to the majority of infographics in circulation today. Thus they are not worth 100 words, never mind 1,000.

Time is also needed to practice and build skills in this area, and the workshop gave me a greater appreciation for the professionals out there, including my brother. Although a novice can quickly grasp the basics of graphic design tools, mastery takes years. On the other hand, with professionals on hand to help, our group of PhD students were able to produce some pretty neat infographics in one long day that did actually convey scientific information.

Which brings us back to comfort. Various audiences struggle to be comfortable with the outcomes of big data analysis, especially if it is scientific. Climate change and other global environmental issues are key examples, as some of our workshop groups grappled with. But if this discomfort and mistrust can be overcome, fantastic infographics are a likely way to do it, because a good picture is something we all can understand, no matter our age, education or the language we speak.

I felt more comfortable trying to create something in the visual language of graphics at this workshop than in a computer programming language at the previous workshop, so I hope that my comfort will be transferred to my audience as I start trying to illustrate my own research. Once I have the information I want to illustrate, of course!

The Bus on the Wheels goes Round and Round

This isn’t a blog about transport. This is a blog about transport analogies which I am writing in an attempt to describe the year now ending.

Picture an iconic American school bus. Big, yellow, snub-nosed and boxy. Inside, symmetrical rows of brown vinyl bench seats, no ergonomics, no seatbelts (or at least not in my day), no comfort unless you scrunched yourself down into a sky-ward-facing foetal position, knees against the back of the seat in front of you, head well-below the sight-line of the driver’s mirror.

I am not saying that 2016 has made me feel like a teenager again, riding that school bus with frozen hair in the darkness of a winter morning.

Personally, this year gone by has been one of maturation, a year of economic security, family building and learning. Even though I have become a student again, I have not been transported back to a retro lifestyle. My family and I have been driving modern transport; smooth, efficient, even innovative. But the world around me in 2016 seems to be on a different road in a different vehicle.

That vehicle is not the American school bus I described. If it were, I’d be a bit less concerned about where we are heading. There are worse places to go at night than depots filled with seas of yellow nestled by highway exits, or to set out each day to serve the future generations of the United States in their receipt of universal education. The vehicle I am thinking of is what the American school bus becomes when and where it is regenerated for a second life:

Amidst the volcanos and violence of Central America, school buses past their sell-by date are sold and refitted with large truck engines. They are given incredibly colourful paint jobs, and christened with religious slogans and iconography. They become public transport vehicles for people of all ages and purposes, and travel, overloaded, up and down mountain roads at impressive speeds with an appalling safety record.

Years ago, as a tourist in Central America, I was told that the drivers of these works of art do not trust themselves to safely convey their vehicle and its passengers between destinations. Rather they believe that God, Jesus, or Mary is responsible for their journey. Thus the religious symbols and the prayers that accompany every trip. If the bus plummets into a ravine, it will be down to a lack of faith rather than a lack of driver training.

Which seems to suit the events of 2016 and the type of vehicle that half the British and American populations have chosen for the rest of the us. These people have chosen faith over fact, trusting to outdated, overloaded, repurposed vehicles of the 20th century rather than trying to design and modify the emerging models of 21st century transport that could much better serve their needs. Nobody is much bothered if busloads of immigrants, war refugees, climate refugees, even children go over the edge. After all, it is no one’s fault that they fell if they did not pray enough, were not born in the right place at the right time, of the right faith. As the well-loved lives of celebrities were also brushed off their seats on the roof this year, the response may have been mournful, but the bus carried on its ill-starred journey.

And as 2017 looms ahead, where will the bus take us, willing and unwilling passengers and drivers alike? My mind turns to a rather prescient song from the 1980’s children’s television show, Fraggle Rock: Catch a Tail by the Tiger. I encourage anyone to look up the lyrics and you’ll see what I mean. We seem to be headed for a topsy-turvy 2017 where our 2016 ex-American school bus might well be going round on its wheels rather than the wheels going round on the bus.

Big Data Busting

You’ve heard the term before. Maybe from me. Big Data. It’s a catchphrase of our time. But have you ever asked what it means? Google’s search engine defines it as a noun referring to “extremely large data sets that may be analysed computationally to reveal patterns, trends, and associations, especially relating to human behaviour and interactions.” And Google should know, right? It’s their day job.

But I had another definition proposed to me at a workshop on the topic last week. Roger Downing of the Hartree Centre in Warrington, part of the Science and Technology Facilities Council, described big data as datasets that were “uncomfortably large to deal with on a single machine”. That’s one of the reasons why the Hartree Centre exists and why I and a group of other PhD students were being treated to a workshop on big data there – they have plenty of machines to deal with the datasets comfortably. But over the course of the week, I began to wonder whether big data was about not just the size of the datasets, but also the data analysis decisions that may be uncomfortable for individual humans to deal with.

Certainly the volume of data and the speed with which it’s generated is staggering for humans or machines. Even though it has to be translated at some point into a plethora of ones and zeros, the datasets themselves are made up of numbers, measurements, text, images, audio and visual recordings, shape files and mixed formats collected and stored in a variety of computer programming languages. The datasets come from sources around the world and are produced by scientists, machines, transactions, interactions and ordinary people. Therefore, it is no surprise that some of the data is meticulous, some is missing and some is mendacious.

And all of it only has value if it can be analysed in such a way that can help people in society make better decisions more efficiently and achieve their goals, whether they be health and well-being or the bottom line.  So if the analysis is uncomfortable for a single machine, then big data analytics requires tools that enable ‘cluster computing’ with processing in parallel and allowances for ‘fault-tolerance’ or duplication of original and subsequent datasets so that information is not corrupted or lost during processing. The performance of such tools are designed and judged for speed, efficiency, ease of use, compatibility and unity, i.e. the more different data types the tool can handle, programming languages it can interact with, and variety of output it can produce within a unified framework, the better.

Of course tools must be used by well-trained data scientists, because the analysis of data and its value depends upon asking the right questions. Those right questions are most likely to be asked if data scientists not only have statistical and computer science skills, but also expertise in their area of study and a combination of creativity and curiosity that seeks new paths for research. Which again, is why we were there, as it is felt in some circles that it may be easier to offer training in statistics and computer programming to those working and researching within specialist areas than to train statisticians and computer scientists in all the disciplines they may encounter in their work with big data. Furthermore, patterns and predictions coming out of big data analysis are not helpful if the data has not been cleaned first and checked for its accuracy, consistency and completeness, a much easier task with specialist knowledge at your disposal. Machines cannot learn if they are not trained on structured and then validated data. And people cannot trust the output without control over the input and an understanding of how data was transformed into information.

And so there is the issue of comfort again. The technology now exists to economically store big datasets and try to merge them even if there is no certainty that added value will result. Machines analyse big data and offer potential audiences instead of actual ones, probabilities and levels of confidence instead of facts. Machine learning and cognitive computing utilise big data to create machine assistants, enhancing and accelerating human expertise, rather than machine workers, undertaking mundane tasks for humans. Thus we enter a brave new world. But I still can’t say I’m entirely comfortable.

Mobility vs Accessibility: new evidence for an old debate

I was at a public exhibition many years ago where I was approached by a rather aggressive environmental campaigner. He told me that if public sector transport planners like me really wanted to promote sustainable travel, then we’d all live and work within the same Local Authority area. Everything we did should be local and we shouldn’t really need to go anywhere, and then we wouldn’t be emitting all that carbon travelling. As I lived in another District from where I was working, albeit only 10-12 miles away, I naturally did no more than nod and smile politely.

Inside, I was thinking: Yes I agree that we need to reduce our transport emissions and impacts on the climate, but my husband is the one that lives next to his work and I had to find a job nearby. Yes I’d like a shorter, more convenient commute, but there wasn’t a job in my field, never mind at the level I was looking for, advertised within my District at the time. Yes I prefer to travel by sustainable modes, but I do take the train to get here, whereas I might have to drive to other jobs at a similar or shorter distance. Yes, but…!

Ok, enough of the protests in my head that clearly have been yearning to break free for far too long. My point in recalling this story is that the man’s superficially inane, impractical argument does have a grounding in a fundamental principle of transport that many transport planners, never mind transport users, often overlook. Transport planners tend to focus on creating and promoting options (read new infrastructure or services) for mobility, rather than accessibility.

Yet people travel for the purpose of accessing a job or a shop or a friend’s house, and travel further if those things they are trying to access are further away. The further they travel, the less mobility options they have, which may result in a poor choice between car-dependence and isolation. The latter I add as we consider the impact of new online technologies on accessibility over mobility. See a great blog on this by @alikirkbride for #LTTMobilityMatters.

Moreover, I have recently discovered that the concept that humans seek accessibility rather than mobility can be backed up scientifically. In the last decade, researchers [1-4] have used big data from mobile phone call records and social media to show that human movement follows certain patterns, namely:

  • Most people can be found in a few predictable places (home, work) most days of the week at the times (night and day) where you’d expect to find them there.
  • Most people make more short trips than long trips, and the distribution of short trips follows a certain pattern, decreasing with distance, up to a threshold.
  • At which point you have a different pattern where people who travel further can be found in expected places more often and have fewer irregular trips.
  • And, those people who travel further tend to live where there is less density – of population, employment, opportunities, activities – than those who travel shorter distances.

It is this last point that is key. None of the studies are looking at mode of travel, but they say something very basic about travel behaviour. Namely, that people are not choosing which trips to make to minimise journey times or distance travelled, even if that may influence modal choice. No, they are choosing which trips to make based on where the destinations are which they are trying to reach. They will choose the nearest destination that meets their need or desire or nearest ‘intervening opportunity’ as one study calls it [2].

Thus, transport planners should be as aware as land use planners of the importance of place-making, of mixed-use development, of walkable neighbourhoods. Discussing those is a whole other blog, so I’ll leave it there, but in a twisted way, that man who chastised me long ago had a point. If we could work at the sort of job we wanted, shop for whatever we needed, socialise with our friends and family and have our children in decent schools, all in the same area as our home, we would probably choose to do so. Then we would have more options for sustainable mobility (e.g. walking and cycling), which would be better for the environment and our health and make us more resilient to unforeseen events. And so transport planners would be planning for accessibility rather than mobility.

  1. Gonzalez, M.C.H., Cesar A. & Barabasi, Albert-Laszlo, Understanding individual human mobility patterns. Nature, 2008. 453(7196): p. 779-782.
  2. Noulas A, S.S., Lambiotte R, Pontil M, and Mascolo C, A Tale of Many Cities: Universal Patterns in Human Urban Mobility. PLoS ONE, 2012. 7(5): p. 1-10.
  3. Isaacman S, B.R., Caceres R, Kobourov SG, Martonosi M, Rowland, J and Varshavsky, A. Identifying Important Places in People’s Lives from Cellular Network Data. in 9th International Conference on Pervasive Computing (Pervasive). 2011.
  4. Song, C.Q., Zehui Qu; Blumm, Nicholas and Barabási, Albert-László, Limits of Predictability in Human Mobility. Science, 2010. 327: p. 1018-1021.