Cities in a Completely Urbanised World

Posted on May 16, 2015 by Michael Batty

urban1

By the end of this century, we will all be living in Cities but what does this really mean? I have given various talks and written various editorials on this prospect but have never really thought much about what this actually means on the ground. Will we all live in lots of really big cities or all one massive planetary city or will we be spaced out on the earth’s surface, connected by the latest communications technologies and living in a kind of decentralised pattern that is more reminiscent of Toffler’s electronic cottage and E. M Forster’s image of us all living isolated but remotely connected lives in his short story The Machine Stops published in 1909. Well none of these I think. What we do know from our social physics that over the last 200 years, indeed probably over the last 5000, is that our cities are patterned and sized in such a way that they follow a rank-size frequency that means there are very few big cities and very large numbers of small. And we know that this pattern seems to predominate come what may. In fact over the last 50 years, we also note that this rank-size distribution has become flatter with more small cities and less big, somewhat counter to what we might think with all the hype about mega-cities. In this editorial, I explore this prospect and argue that maybe the future will be a little more spread out than we currently imagine. Anyway if you want to read my editorial click here or click on the image above. If you want to see my TEDxLondon talk on this from December 2013, go to YouTube – click here for the video and here for the powerpoint, and if you want to read my first commentary on this in Environment and Planning A, our sister journal to B, click here.

 

Posted in city size, Hierarchy, rank size, Scaling | Leave a comment

A History of Transport Modelling

Posted on May 9, 2015 by Michael Batty

Boyce-Williams

Certainly one of the best books ever on transport modelling. We have been waiting for this sort of book for a long time. Anyone who wants to figure out the reasons why different kinds of transport model have been developed during the last 60 years must read this book. It starts at the beginning round about 1953 and it brings the field up to date to 2015 covering many different approaches to models from aggregative gravitational to activity-based and on to agent-based but covering equilibrium, assignment and a host of policy issues that have directed the field over several generations of models and model-builders.

What is so good about this book is that it is intelligible and non-mathematical. Stephen Hawking says in his introduction to A Brief History of Time that his publishers advised him that the potential readership of his book would drop by half each time he introduced an algebraic equation into the manuscript, and accordingly it became a best seller. Like Hawking before them, Dave Boyce and Huw Williams are experts in the mathematics of their field, in this case transport, with Dave Boyce making pioneering applications in equilibrium analysis and Huw Williams inventing discrete choice theory in transport modelling in parallel with Ben Akiva, McFadden and others who began to introduce microeconomic foundation to transport in the 1970s. This book however simply explains all this in non-mathematical terms, providing a wonderful historical perspective and really clear exposition of the way different models and methods in the simulation of transport actually work.

I believe that this book should be read by everyone involved in transport modelling. It makes a wonderful companion to Otuzar and Willumsen’s Modelling Transport (Wiley, 2011) that is a technical and mathematical treatment of the field. Of course the publishers have priced it way out of sight and they should be encouraged to offer it much more cheaply as a soft back. It is in fact more modestly priced as as an e-book. But in the meantime, it is well worth getting hold of and making its existence known to all in the field.

Posted in Flows, Interactions, LUTI models, Transport Models, Urban Models | Leave a comment

The Fractured Nature of British Politics

Posted on May 1, 2015 by Michael Batty

fracture

The Morning After: Predictions closer than all of us thought,  a Divided Britain

Carlos, Elsa, Duncan and myself (Mike) decided to explore next week’s British election using some of our social physics, specifically our work on uncovering urban hierarchies through percolation theory, which basically consists on looking at the connectivity of ‘representative’ areas in the street system.

This might seem an arcane way of proceeding but when we examine England, Scotland and Wales as a giant connected cluster, and then break it up by successively reducing the distances between its nodes, we first disconnect the periphery – the Scottish islands – and then quite suddenly when the threshold hits 1.4 kms, Scotland breaks off from the rest, pretty much evoking our sentiments about Scottish independence.  Reducing this further, the North and West split from the South East at around 900m and this represents the fault line that as a young student in the early 1960s, was introduced to me as the North-South divide. After this,  Wales and the West Country split off separately, evoking shades of Welsh and Cornish independence. Once we hit 300m, the big cities appear. At the same time, many of the little cities fill in the backcloth.

You could be forgiven for thinking that this is the way the British electorate might vote in next week’s election given all the hype about Scot Nats, the imminent demise of the Liberal Democrats, and the influence of the new parties such as UKIP which could be massive or could be negligible. We don’t know whether or not there will be a last minute bounce and what kind of bounce, dead cat, or otherwise.

Anyway we have had a go at producing our own predictions. And we have placed a paper in the arXiv (which will be available there next Monday) but we would like you to look at here – Click. Please re-tweet it as we want some feedback on this approach because it is much wider than next week’s election per se for it represents a new way of thinking about cities and regions and nations in this connected age. Elsa has also put our more basic paper on the methodology up at the arXiv too and you can get that here too directly.

You might also want to look at our percolation movie too which is rather neat and you can access by clicking in the link here.

Posted in allometry, city size, Hierarchy, Scaling | Leave a comment