So where exactly did The Proclaimers walk 500 miles to?

Leith (centre) and Firth of Forth looking northwest.. Image: RuthAS/Wikimedia Commons.

In their famous 1988 single I’m Gonna Be (500 miles), Scottish twins duo the Proclaimers declared their devotion to a woman by saying they would walk 500 miles, and then 500 more, to spend the rest of their lives with her.

But where exactly did they walk to?

I’ve seen several attempts to solve this conundrum, but these have mainly focused on radial distance – in other words, just drawing a straight line on a map. This doesn’t take into account the geography of Great Britain. In the real world, roads curve and obstacles like rivers and seas block the route – not even the Proclaimers can walk on water. So I attempted to solve the riddle using mathematical graph theory.

Graph theory is the study of networks made up of points (known in graph theory speak as “vertices”) connected by lines or “edges”. Every time you look up a driving route or search for a train journey, graph theory is what lets your computer calculate all the available routes and work out which one is fastest, shortest or cheapest.

To plan the Proclaimers’ route, I need to create a graph of the road network of Great Britain. Fortunately Ordnance Survey provides an openly licenced vectorised dataset called Open Roads which I downloaded and converted it into an “adjacency matrix” – effectively, a huge table containing all the road junctions and road ends (the vertices) and the road segments connecting them weighted by length in metres (the “edges”).

The song featured on the Proclaimers 2nd album Sunshine on Leith, the Edinburgh suburb where the band originate from, so it’s a reasonable assumption that they started their walk in the town. The Town Hall, which houses Leith Theatre, seems a likely place to start.

Walking 500 miles

Road graph, overlaid on OS Open Map Local, of area around Leith Town Hall (shown by red star). Image contains OS data © Crown copyright and database right (2019), OGL Licence.

So our task is to traverse every walkable road in Great Britain, without doubling back on ourselves, to find points exactly 500 miles from Leith Town Hall, without using any public transport. Luckily, the OS Open Roads dataset contains the road type attribute so I can filter out motorways and other non-pedestrian roads – after all, they walked, not drove, those 500 miles.

It’s a sizeable graph consisting of 3,078,131 vertices and 7,347,806 edges so represents a significant mathematical challenge, so I used Graphics Processing Unit (GPU) computing. GPUs are the powerful parallel computation engines contained in graphics cards, which are normally used to render 3D graphics for video games but can also be used to perform mathematical calculations.

I used NVIDIA’s new open source accelerated data science platform, RAPIDS, and an NVIDIA Quadro GV100 GPU, to perform the computation which uses a parallel algorithm to solve the Single-Source Shortest Path (SSSP) problem.

I then built the graph, applied SSSP, and found all results exactly 500 miles from Leith Town Hall, which took less than three seconds in RAPIDS.

This yields two possible destinations, both in Cornwall, the first of which is a remote farm 3 miles from Mevagissey which appears an unlikely destination.

Road graph showing The Meadows near Mevagissey, Cornwall (shown by yellow star). Image contains OS data © Crown copyright and database right (2019), OGL Licence.

The second result is the appropriately named Lusty Glaze Road in Newquay.

Road graph showing central Newquay and Lusty Glaze Road (shown by yellow star). Image contains OS data © Crown copyright and database right (2019), OGL Licence.

Given the urban location, overlooking the beautiful Lusty Glaze Beach, this would appear to be the most likely destination to fall down at her door.

 

Lusty Glaze Beach, with lots of doors to fall down at. Image: Nilfanion/Wikimedia Commons.

The walk would have taken The Proclaimers through all three constituent countries of Great Britain, passing through central Edinburgh, Peebles, crossing into England north on Longtown, Carlisle, Penrith, Kendal, Lancaster, Preston, Wigan, Warrington, Whitchurch, Shrewsbury, Ludlow, Hereford, entering Wales at Monmouth, Chepstow, crossing the River Severn back into England via the M48 pedestrian bridge, Avonmouth, Bridgewater, Taunton, Tiverton, Okehampton, Bodmin and St Columb Major before finally arriving in Newquay.

The walking route from Leith to Newquay: click to expand. Image: contains OS data © Crown copyright and database right (2019), OGL Licence.

Walking 500 more

But perhaps, having walked all that way to Newquay, the woman wasn’t to be found so they had to walk 500 more in order to find her.

This yielded 11 possible destinations across Southern Scotland: Glenwhilly, Kilmarnock, Strathaven, two destinations in the Rutherglen area of Glasgow, Livingston, Haymarket in Edinburgh and four destinations in Leith, including the Victoria Swim Centre, Leith Walk, the Tesco superstore and the Town Hall and theatre where they originally started.

Possible destinations in southern Scotland to walk 500 more miles from Newquay (shown by yellow stars). Image: contains OS data © Crown copyright and database right (2019), OGL Licence.

Conclusion

So I would suggest the most likely explanation is that the Proclaimers looked for the woman at Leith Town Hall & Theatre where they were performing, mistakenly thought she’d gone to Newquay, and walked all the way there.

However, it looks like the woman had simply popped round the corner, maybe for a walk, a swim or to shop in Tesco, so they had to walk all the way back to find her.

Leith Walk. Image: Kim Traynor/Wikimedia Commons.

If you’d like to try this for yourself, I’ve made the Python Notebooks, together with links to the source data, freely available on GitHub.

John Murray is a data scientist and visiting research fellow in the Geographic Data Science Lab at  the University of Liverpool. He tweets as @MurrayData.


 

 
 
 
 

Community-powered policies should be at the top of Westminster’s to do list

A generic election picture. Image: Getty.

Over the past five decades, political and economic power has become increasingly concentrated in the UK’s capital. Communities feel ignored or alienated by a politics that feels distant and unrepresentative of their daily experiences.

Since the EU referendum result it has become something of a cliché to talk about how to respond to the sense of powerlessness felt by too many people. The foundations of our economy have been shifted by Brexit, technology and deindustrialisation – and these have shone a light on a growing divergence in views and values across geographies and generations. They are both a symptom and cause of the breakdown of the ties that traditionally brought people together.

As the country goes through seismic changes in its outlook, politics and economy, it is clear that a new way of doing politics is needed. Empowering people to take control over the things that affect their daily lives cannot be done from the top down.

Last week, the Co-operative Party launched our policy platform for the General Election – the ideas and priorities we hope to see at the top of the next Parliament’s to do list. We have been the voice for co-operative values and principles in the places where decisions are made and laws are made. As co-operators, we believe that the principles that lie behind successful co‑operatives – democratic control by customers and workers, and a fair share of the wealth we create together – ought to extend to the wider economy and our society. As Labour’s sister party, we campaign for a government that puts these shared values into practice.

Our policy platform has community power at its heart, because the co-operative movement, founded on shop floors and factory production lines, knows that power should flow from the bottom up. Today, this principle holds strong – decisions are best made by the people impacted the most by them, and services work best when the service users have a voice. Our policy platform is clear: this means shifting power from Whitehall to local government, but it also means looking beyond the town hall. Co-operative approaches are about placing power directly in the hands of people and communities.


There are many great examples of Co-operative councillors and local communities taking the lead on this. Co-operative councils like Oldham and Plymouth have pioneered new working relationships with residents, underpinned by a genuine commitment to working with communities rather than merely doing things to them.

Building a fairer future is, by definition, a bottom-up endeavour. Oldham, Plymouth and examples like the Elephant Project in Greater Manchester, where people with experience of disadvantage are involved in decision-making, or buses in Witney run by Co-operative councillors and the local community – are the building blocks of creating a better politics and a fairer economy.

This thread runs through our work over the last few years on community wealth building too – keeping wealth circulating in local economies through growing the local co-operative sector. Worker-owned businesses thriving at the expense of global corporate giants and private outsourcers. Assets owned by communities – from pubs to post offices to rooftop solar panels.

And it runs through our work in Westminster too – with Co-operative MPs and peers calling for parents, not private business, to own and run nurseries; for the stewards of our countryside to be farmers rather than big landowners; and for workers to have a stake in their workplaces and a share of the profit.

Far from being ignored, as suggested in last week’s article on community power, our work has never been more relevant and our co-operative voice is louder than ever.

Anna Birley is policy offer at the Co-operative party.