A Markov Chain Model of Land Use Change

Recently published:

Minneapolis Aerial
Minneapolis Aerial

The set of models available to predict land use change in urban regions has become increasingly complex in recent years.  Despite their complexity, the predictive power of these models remains relatively weak.  This paper presents an example of an alternative modeling framework based on the concept of a Markov chain.  The model assumes that land use at any given time, which is viewed as a discrete state, can be considered a function of only its previous state. The probability of transition between each pair of states is recorded as an element of a transition probability matrix.  Assuming that this matrix is stationary over time, it can be used to predict future land use distributions from current data.  To illustrate this process, a Markov chain model is estimated for the Minneapolis-St. Paul, MN, USA (Twin Cities) metropolitan region.  Using a unique set of historical land use data covering several years between 1958 and 2005, the model is tested using historical data to predict recent conditions, and is then used to forecast the future distribution of land use decades into the future.  We also use the cell-level data set to estimate the fraction of regional land use devoted to transportation facilities, including major highways, airports, and railways. The paper concludes with some comments on the strengths and weaknesses of Markov chains as a land use modeling framework, and suggests some possible extensions of the model.

Open Traffic

Open Traffic is a new initiative to make GPS traffic data open and available to the public and others, by linking it with OpenStreetMap. It is organized by Conveyal, MapBox, and MapZen with support from the World Bank. The Code is of course open source as well.

OpenTraffic is a free, global traffic speed data set linked to OpenStreetMap built with open source software.

Traffic speed data is a critical input to many transportation related applications. Fortunately many users who need speed data also produce the inputs necessary to create annonmyized traffic statistics.

OpenTraffic provides the space and tools to share traffic statistics from connected vehicles and mobile services. We support the development of analysis and routing tools that enable cities, businesses, and individuals to make use of this data.

How it Works

OpenTraffic connects anyone with real-time or archived GPS location data to processing technology, data storage, and routing and analysis applications.

Location data privacy is paramount. We allow contributors to share anonymized traffic speed statistcs from derived GPS data without disclosing individuals’ location information. In return, data contributors help build a global traffic speed data set that can be used in routing and analysis applications.

The OpenTraffic platform is comprised of several components to make it easy to share and use traffic data:

GPS Probes

GPS probe data can be generated from a variety of sources, including mobile applications or fixed GPS hardware. GPS data can be processed in real-time or archived and transmitted for batch analysis. The OpenTraffic platform has a variety of open source tools to help you load your GPS data from existing sources or connect to Amazon AWS Kinesis streams to manage real-time flows of any size.

Traffic Engine

GPS data is linked to the OpenStreetMap network via Traffic Engine. Data is converted from GPS locations to roadway speed observations and anonymized before being aggregated. As open source software, you control where Traffic Engine is deployed, allowing full control over GPS trace data. Simply install Traffic Engine and load your GPS data to start generating traffic data.

Data Pool

Once anonymized, traffic statistics are added to the global OpenTraffic data pool. By pooling data many different data sources are merged together to provide a seamless global data set, free for use by any application.

Get Involved

We are working with vehicle fleet operators, app developers, and governments to develop and operate the OpenTraffic platform. Learn how you can contribute and benefit: Contact Us

TeMA: Journal of Land Use, Mobility and Environment

I have recently been named to the Editorial Board of TeMA: Journal of Land Use, Mobility and Environment. This is an Italian open access journal on things I am obviously interested in. Though it is based in Italy, many of the articles are in English, the international language of science. The archive of past issues is here. I copy it below:




Vol 8, N° 1 (2015): Cities, Energy and Climate Change

Urban population is rapidly reaching two thirds of the global population; thus, cities are the core of a change that need to be driven: the rapid urban population growth involve a large energy consumption and high greenhouses gas emissions which drive cities to face environmental challenges like as climate changes and energy resources’ scarcity. As remarked by the last Report of the United Nations on Sustainable Development, climate change is one of the greatest challenges of our time and adequate strategies capable of mitigating and adapting to its impacts represents an immediate and urgent global priority. This issue of the TeMA focues on the topic of Cities, Energy and Climate Change, focusing on current strategies addressed to mitigation and adaptation.



Vol 7, N° 3 (2014): Smart City Challenges: Planning for smart cities. Dealing with new urban challenges

The role of urban planner is changing: ICT and big data availability, enabling them to monitor and analyse large amount of data and information, may contribute to better understand and plan the city, improving efficiency, equity and quality of life for its citizens and its capacity to face future challenges. Big data availability is shifting our focus away from the long to the very short term, affecting urban planner’s efforts on generating an effective knowledge base for planning.

2014: INPUT 2014 – Smart City: planning for energy, transportation and sustainability of the urban system

This special issue collects a selection of peer-review papers presented at the 8th International Conference INPUT 2014 – Innovation in Urban and Regional Planning, titled “Smart City: Planning For Energy, Transportation and Sustainability of Urban Systems”, held on 4-6 June in Naples, Italy. The issue includes recent developments on the theme of relationship between innovation and city management and planning.

Vol 7, N° 2 (2014): Smart Cities Challenges: Smart Communities Between E-Governance and Social Participation

Information and communication technology (ICT) is producing urban environments that are quite different from anything that we have experienced before. Cities are becoming smarter (or rather their population is becoming smarter) and can automate functions serving individual persons, buildings and traffic systems. At the same time, sensors streaming data, are giving rise to entirely new forms and patterns that enable us to watch how cities and their populations are responding in almost real time. Big data, open data, wireless sensor networks may represent basic tools for re-thinking our development model, decoupling economic growth from environmental degradation; re-designing our planning tools in face of the new challenges that cites have to deal with; creating inclusive and sustainable communities. The new ICT capabilities will allow the rising of a new dimension of the urban social capital and a new consciousness of citizens in the monitoring of the evolution process of the city.

Vol 7, N° 1 (2014): Smart Cities Challenges: Smart Environment for Sustainable Resource Management

The role of urban planner is changing: ICT and big data availability, enabling them to monitor and analyse large amount of data and information, may contribute to better understand and plan the city, improving efficiency, equity and quality of life for its citizens and its capacity to face future challenges. Big data availability is shifting our focus away from the long to the very short term, affecting urban planner’s efforts on generating an effective knowledge base for planning.
This TeMA issue focuses on the theme of Planning for Smart Cities and invites contributions investigating innovative approaches, methods, techniques, tools for supporting urban and spatial plans (at different scales) on the following themes: Functional Densification; Social Housing; Urban Rehabilitation and Renewal; City Competitiveness in Economic Crisis; Brownfield Transformation; Maintenance, Upgrading and Innovation of Urban Infrastructures; Regeneration of Existing Building Stock; Reassessment of Urban Standards.



Vol 6, N° 3 (2013): Smart Cities: Research, Projects and Good Practices for Infrastructures

The volume n.6 of TeMA Journal of Land Use, Mobility and Environment deals with the topic of Smart City and this third issue deals in particular with the theme of Smart Urban Infrastructural systems. The main subjects that this issue point out are innovation of networks and infrastructural systems for people and goods mobility; advanced technologies of communication; intelligent systems for energy production and distribution; monitoring systems for provision of real time information on different aspects of urban life (mobility, climate conditions, safety and so on). In this broader context one of the key theme is the role of ICT in innovating government and the policy decision processes: by enhancing the linkages between various governmental and social organizations, ICT supported knowledge flows (Socio Technical System) is a mean for sustaining innovation in the public sector since they enables governments to better cope with the uncertainties of a complex environment.

Vol 6, N° 2 (2013): Smart Cities: Researches, Projects and Good Practices for Buildings

This issue of the volume n.6 “Smart Cities” focuses on ideas, projects and good practices with specific reference to the building scale, keeping in mind that the urban fabrics have to be seen not only as structure following the most advanced technological solutions but, above all, as constructions capable of an effective interaction with urban context, capable of reducing energy consumption, optimizing the use of space, minimizing impacts on natural resources, assuring the safety of inhabitants, also through an efficient use of available technologies.
Therefore, based on a systemic approach, this issue collects and promotes ideas, projects and good practices at building scale, able to affect the quality of everyday life, without ignoring the complex tissue of physical, functional and environmental relationships between buildings and the urban systems they belong to.


Vol 6, N° 1 (2013): Smart Cities: Researches, Projects and Good Practices for the City

The concept of the smart city has been quite fashionable in the policy arena in recent years and the question of how we can live “smartly” in a city has become the focus of policymakers and private industry. The label smart city is still quite a fuzzy concept and is used in ways that are not always consistent. However, starting from a general definition, what is central to the concept of the Smart City and what makes it differ from ‘sustainable cities’ or ‘ECO cities’ is the use of Information and Communication Technologies (ICTs) in the process of creating a more sustainable city but also the availability and quality of knowledge communication and social infrastructure.

This first issue of TeMA, Journal of Land Use, Mobility and Environment, volume no.6 deals with the subject of Smart City with reference to the urban scale. Accordingly, the papers tackle the different aspects characterizing a  smart urban development: ranging from the more specifically economic ones, targeted to the implementation of strategies expected to improve competitiveness of cities in the global scenario; to those more involved in environment questions aimed at identifying strategies for improving the city capability of facing the important challenges given by the ongoing climate change as well as by the ever-growing reduction of traditional energy resources, paying particular attention to the improvement of urban mobility and energy saving as well as of those connected with the quality of life of communities, with specific attention to the participation to decisions-making processes, equity in the access to resources, individual and collective safety, social cohesion.



Vol 5, N° 3 (2012): Mobility and Competitiveness

This issue focuses on the relations between competition among regions and cities and policies and/or infrastructural facilities related to mobility. In other words, the issue explores the contribution that infrastructural systems and/or procedures and tools for mobility planning and management can provide to the raise of the levels of competitiveness that cities achieve. The broad topic  include both theoretical contributions and others more closely linked to policies/practices for mobility that positively affect the efficiency and livability of urban systems, increasing their potential for attracting businesses and families.

Vol 5, N° 2 (2012): Resilient city

The Resilience concept has been largely debated in different disciplinary fields since the Seventies. An important contribution to the definition of Resilience itself and to the development of a peculiar focus on Urban Resilience has been recently provided by studies and researches on climate change. In this field, resilience has been defined as a set of adaptive capacities of urban systems dealing with different stress factors and, in particular, with phenomena of climate change and oil resources scarcity. A resilient city is defined as a city capable of absorbing shock and/or disturbances, without suffering significant alterations in its functional organization, its structure and identity features. According to these studies, this issue of TeMA focuses on national strategies and actions implemented both in  European and in different national and urban contexts, in order to increase urban resilience in face of the main factors threatening their development and, in particular, of climate change, related natural hazards and oil resources scarcity.


Vol 5, N° 1 (2012): Landscapes of Urban Sprawl

Urban sprawl processes characterize the landscape of the areas surrounding cities. These landscapes show different features according to the geographical area that cities belong to, though some common factors can be identified: land consumption, indifference to the peculiarities of the context, homogeneity of activities and building typologies, mobility needs exasperatedly delegated  to private cars. Furthermore, these processes increasingly develop while land use planning seems unable – due to the lack of  capacities or of will – to counteract the causes, with multiple effects, which can be summarized in an overall reduction in quality of life.
Scientific community has been questioning about the need to curb urban sprawl processes  for many decades, since when large suburbs have been changed from desirable residential places to areas characterized by poor relationships and social qualities.



Vol 4, N° 4 (2011): Mobilità e conflitti

L’esercizio, la realizzazione o la previsione di insediamento di un sistema di mobilità possono generare diverse forme di conflittualità. Queste ultime possono riguardare principalmente la sfera socio-territoriale ed il rapporto fra infrastruttura (in generale grandi sistemi di trasporto e scambiatori) e collettività locale, interessata dai mutamenti territoriali indotti e esposta agli impatti che si originano per effetto del sistema di trasporto.

In prima ipotesi, è possibile identificare una serie di conflitti riconducibili a fattori quali: la tipologia di infrastruttura, la scala dell’intervento, il tipo di impatto generato, le caratteristiche delle collettività coinvolte, la distribuzione territoriale delle infrastrutture di mobilità, la tipologia di spostamento, ecc.

Il numero si pone l’obiettivo di analizzare le possibili ed eterogenee forme di conflittualità, estendendo l’approfondimento anche a forme di conflitto che possono riguardare: le procedure di concertazione, i percorsi di ricerca del consenso, ma anche gli squilibri nell’erogazione del servizio ed i conflitti indotti fra classi diverse di utenti dalle nuove politiche di gestione delle infrastrutture (per esempio considerando le nuove opportunità di spostamento offerte dalla rete A/V).

Un ruolo particolarmente rilevante va riservato alla riflessione sugli impatti, gli squilibri e le discrasie generate sul “sistema  ambiente” dalle nuove infrastrutture di mobilità che intervengono a modificare gli assetti orografici e le specificità ambientali di siti di consistente valore (territori alpini, insulari, costieri, etc.) ambientale e per i quali sussiste un forte senso di appartenenza radicato nelle comunità locali.


Vol 4, N° 3 (2011): Mobilità e grandi progetti

Questo numero di Tema si occupa della realizzazione di grandi progetti infrastrutturali, con particolare riferimento al rapporto tra grandi progetti e competitività territoriale, alle tecniche e ai metodi per valutare gli impatti dovuti alla realizzazione di interventi nel settore dei trasporti, all’efficacia degli investimenti nel settore dei trasporti su scala europea, ai cambiamenti nei sistemi metropolitani indotti dall’attuazione dei progetti infrastrutturali, alla valutazione, 10 anni dopo la Legge Obiettivo, delle implementazioni di infrastrutture strategiche in Italia, agli impatti dei grandi progetti infrastrutturali sul paesaggio e sull’ambiente.


Vol 4, N° 2 (2011): Green Mobility

La mobilità delle persone e delle merci è largamente riconosciuta quale presupposto imprescindibile per la crescita economica e lo sviluppo della società, elemento strategico per lo sviluppo competitivo di città e regioni e diritto fondamentale delle collettività. Nel contesto europeo i trasporti costituiscono uno dei settori economici più rilevanti ma, anche, uno dei principali fattori di deterioramento della qualità ambientale e della vivibilità, soprattutto nelle grandi aree urbane: inquinamento atmosferico e acustico, consumo di fonti energetiche non rinnovabili, consumo di suolo, congestione, incidentalità sono tra i principali costi ambientali connessi ai trasporti.

Pertanto, questo numero di TeMA intende focalizzare l’attenzione sulle strategie e sulle messe in campo sia in ambito europeo che in diversi contesti nazionali ed urbani, per ri-orientare la politica dei trasporti verso obiettivi di sostenibilità, al fine di garantire una complessiva crescita della mobilità e, nel contempo, una significativa riduzione dei costi ambientali ad essa associati.


Vol 4, N° 1 (2011): Unità d’Italia e Mobilità

L’unificazione italiana nel 1861 è stata l’inizio di grandi modifiche all’interno del paese, ha cominciato, tra gli altri, un processo di unificazione della rete di mobilità nazionale, per lungo tempo fossilizzata all’interno dei confini dei diversi stati . Il processo di unificazione si è basata sulle reti esistenti; il risultato fu che le aree attrezzate con le reti più avanzate sono state favorite, mantenendo la propria supremazia nella competizione con le aree meno sviluppate. Lo sviluppo della rete nazionale si è basata, per molto tempo, sul miglioramento della rete ferroviaria. Solo dopo l’inizio della motorizzazione di massa, dopo la seconda guerra mondiale, la rete autostradale ha prevalso assorbendo, a partire dagli anni Sessanta, la maggior parte degli investimenti nazionali.L’obiettivo di questo numero di TeMA è quello di indagare lo stato dei sistemi di mobilità in Italia secondo una prospettiva storica. L’unità italiana è stata, infatti, una opportunità rilevante per influenzare profondamente diversi settori, tra cui quello delle infrastrutture.



Selected Papers 2010

This special number is a selection of papers published in TeMA 2010 volume and is the second item completely in English. The selected papers are works previosly published in Italian and now presented in a different layout collected into a unique item.

Vol 3, N° 4 (2010): Small/Large Urban Projects

Questo quarto numero dell’anno 2010 vuole fare il punto, con la illustrazione di progetti e casi di studio, sui processi di integrazione della progettazione e quindi della realizzazione delle infrastrutture di trasporto, puntuali o lineari, con gli interventi di trasformazione della città e del territorio. Nel vasto panorama degli interventi progettati o realizzati in questi ultimi anni, in Italia e all’estero, abbiamo privilegiato le due tipologie che consentono una sintesi più immediata degli approcci, dei sistemi di intervento, delle soluzioni progettuali adottate e dei problemi non risolti che questa metodologia pone in essere: i Large scale projects e gli Small projects.


Vol 3, N° 3 (2010): Moving for Leisure

Partendo dalla consapevolezza che lo spostamento sia una condizione necessaria allo svolgimento della pratica turistica tout court e di quella urbana in particolare, il numero affronta il tema della mobilità turistica nelle aree urbane, analizzando alcuni principali interventi messi in campo per adattare l’offerta di trasporto alle richieste di un’utenza temporanea ma con una forte incidenza sul bilancio economico della città.

Vol 3, N° 2 (2010): City Logistics

Il numero affronta il tema della city logistics, ovvero di quel settore della logistica che studia ed attua soluzioni per l’ottimizzazione del trasporto delle merci nelle aree urbanizzate. In un’epoca in cui il fenomeno dell’urbanizzazione è a livelli mai prima raggiunti la city logistics rappresenta un tema di grande attualità sia per il trasporto merci, attività essenziale per la sopravvivenza delle persone, che per la qualità della vita, atteso che il trasporto in genere e quello delle merci in particolare sono tra le cause principali dell’inquinamento ambientale.

Vol 3, N° 1 (2010): Urban Planning and Mobility

Urban Planning and Mobility propone un approfondimento sul tema del governo integrato trasporti-territorio. Questa forma di coordinamento deve essere finalizzata al raggiungimento di un equilibrio tra le politiche urbanistiche come input per la programmazione dei sistemi di trasporto, mantenendo salda l’ipotesi che il sistema di trasporto è un determinante per l’evoluzione del sistema territoriale.



Vol 2 (2009): Selected Papers 2009

This special number is a selection of papers published in TeMA 2009 volume and is the first item completely in English. The selected papers are works previosly published in Italian and now presented in adifferent layout collected into a unique item.

Vol 2, N° 4 (2009): Flussi Metropolitani

Il numero Flussi Metropolitani propone un approfondimento sul tema della mobilità alla scala sovra-comunale ed in particolare sul sistema di relazioni esistenti tra i processi di espansione metropolitana e il ruolo della rete e dei sistemi di mobilità. L’espansione della città alla scala metropolitana modifica l’organizzazione dello spazio territoriale e dei sistemi coinvolti, in particolare quelli residenziali, ambientali, produttivi, delle attrezzature e dei servizi pubblici; non ultimo il sistema della mobilità, che innerva i territori e ne caratterizza l’efficienza, al punto che, in molti casi, i ritardi infrastrutturali arrivano a condizionarne l’organizzazione e la competitività.

Vol 2, N° 3 (2009): Porto, mare e città

Questo numero di TeMA propone un approfondimento sul rapporto tra la città e il mare. L’idea guida è quella di considerare i waterfront urbani e i nodi portuali come aree di confine e allo stesso tempo di cerniera tra le aree metropolitane e il mare. I fronti marittimi urbani e le aree portuali, proiettati sul mare e parte integrante del contesto territoriale in cui sono localizzati, “aree sensibili” sia in termini fisico-funzionali che di pianificazione e gestione.


Vol 2, N° 2 (2009): Mobilità e sicurezza

Questo numero di TeMA fornisce un approfondimento sul tema della sicurezza applicato ai sistemi di trasporto, che, come attrezzature di importanza strategica alla vita quotidiana delle comunità, costituiscono elementi esposti ad elevata vulnerabilità sia in relazione all’uso degli stessi, sia rispetto al verificarsi di fenomeni calamitosi. Il numero affronta i diversi aspetti del tema della sicurezza applicato ai sistemi di trasporto di persone e merci, per i diversi modi di trasporto e con differenti approcci.


Vol 2, N° 1 (2009): Politiche della sosta e città

Il numero fornisce elementi di riflessione ed approfondimento sul ruolo del governo della sosta per la mobilità sostenibile nelle aree urbane, illustrando metodi, strategie, strumenti ed interventi da implementare attraverso lo studio della recente bibliografia e l’analisi di best pratices nazionali e internazionali.



Vol 1, N° 3 (2008): Soft Mobility

Il numero affronta il tema della mobilità dolce (pedonale e ciclabile) alla scala urbana e alla scala vasta, attraverso riflessioni toeriche e studio di pratiche innovative in Italia ed in Europa.


Vol 1, N° 2 (2008): Mobilità e grandi eventi

Il numero affronta il tema della pianificazione e gestione dei sistemi di trasporto e della mobilità in occasione dei grandi eventi. Attraverso riflessioni teoriche ed applicazioni, si analizzano le scelte messe in campo per rispondere alla necessità sia di rendere accessibile l’area dell’esposizione a grandi flussi di visitatori, sia di integrare le nuove opere nel disegno di sviluppo della città.


Vol 1, N° 1 (2008): High Speed Cities

Questo numero della rivista affronta un argomento di grande interesse per chi vuole studiare le relazioni tra sistemi urbani e sistema della mobilità: le High Speed Cities. L’obiettivo è riflettere sui molteplici effetti, non ancora sufficientemente indagati, che l’entrata in esercizio dell’Alta Velocità ferroviaria può avere, da diversi punti di vista e a diverse scale, sull’organizzazione spaziale e funzionale dei sistemi urbani coinvolti.



Vol 1 (2007): Numero Zero

Con il numero zero di TeMA, ed il lancio della nuova rivista l’intenzione è dare il nostro contributo alla costruzione di nuove competenze, scientifiche e allo stesso tempo professionali, su uno degli argomenti di sempre maggior interesse per chi studia e opera nei settori delle trasformazioni fisiche della città e del territorio: l’integrazione tra le discipline che studiano le trasformazioni urbane e quelle che affrontano le tematiche del governo della mobilità. Direi di più, forse è arrivato il momento di porci un obiettivo più ambizioso: costruire un nuovo corpus di conoscenze teorico-metodologiche che, superando gli steccati che segnano il confine – del tutto apparente – tra queste discipline, sia in grado di formulare soluzioni nuove ai problemi che oggi continuiamo ad affrontare con i vecchi arnesi della cultura scientifica del secolo scorso.

Open Source Trip Generation

We have long known in the transportation planning community that the use of trip generation for local area review, and ITE’s procedure for estimating trip generation is broken in any number of ways. Shoup’s Truth in Transportation Planning is a classic critique of the problems.

While we could (and perhaps should) throw the whole kit and caboodle into recycling, in practice trip generation methods will be with us decades from now (even as traditional work, shopping and driving disappear). So there is a small academic movement to make the methods better. The most recent issue of JTLU 8(1) has a special section on Trip Generation, including several papers about how to adjust and improve ITE’s Trip Generation methods based on better data.

Part of the problem is that ITE is functionally a for-profit organization, and makes bank on selling the Trip Generation Manual and associated software (recognizing the fact that use of ITE Trip Generation rates is ensconced in law and regulation).

What has long been needed is an open source database of trip generation studies so that better fits to actual site conditions can be used in analysis. I recall in my youth some engineers in Montgomery County, Maryland trying to set something up, but this was well before the world wide web made that easy.

Fortunately that day is upon us. Mike Spack and company have set up TripGeneration.org, which is populated with open access trip generation studies (licensed under a Creative Commons license), and for which they hope to grow the data set. This is new, and I assume as it grows the data will get better and better, as will the methods for inputting and extracting data. Kudos to Mike, Nate, and others at Spack Consulting for getting this going. I look forward to seeing where this goes, as Big Data and new sensors make data collection increasingly ubiquitous.

Preserving Data for Future Research

I worked with the University of Minnesota libraries on a pilot data curation program. I have discussed this before. The article about the project: Preserving Data for Future Research is online now, and is in their Continuum Magazine. There is a rare photo of me smiling.

Professor David Levinson

“This is a service that the Libraries can provide and nobody else on campus is currently providing,” said Lisa Johnston, a University of Minnesota librarian, who also is Co-Director of the University Digital Conservancy. Johnston is working on a plan to meet the federal mandate.

“This is just a new type of resource that we will be providing,” she said. “It’s a natural extension of library services.”

Johnston led a pilot data curation project last year that involved faculty members, researchers, and students representing five different data sets. The project leveraged the Libraries existing infrastructure, the University Digital Conservancy, the institutional repository for the University of Minnesota (conservancy.umn.edu).

“Feedback from the faculty in the pilot was very positive and anticipated that this service might satisfy the upcoming requirements from federal funding agencies,” Johnston said. Now she’s working toward building a repository for the campus, which may be open for business later this fall.

“University libraries are the natural repository for research conducted at a particular university,” said David Levinson, professor in the Department of Civil Engineering. Levinson – who conducts research in the area of infrastructure, particularly transportation infrastructure – currently maintains some of his research data on his office desktop computer.

“I won’t be here in 20 years; I’ll be retired. What will happen to the data sets when I retire?” he asks “What if someone forgets to migrate it?”

Levinson was involved in the pilot study. He called it a “step in the right direction, but it’s a baby step,” citing potential lack of resources and compliance as two challenges to a fully functioning data curation repository.

“You could probably have one librarian for every department at the University … who could have a full-time job collating and collecting the data for that department each year,” he said, noting that a funding model has not yet been established. He adds “[The funding] should come from the grants.”

So, why is it important for publicly funded research data to be preserved?

“First of all, the data is oftentimes unique, you could never recreate it,” Johnston said. “It’s also very expensive. And what do you get out of it? One, two, five papers? You could instead make that underlying research data available so that other researchers can take a look at the data, re-analyze it and come up with new results – perhaps competing results, perhaps validating results.”

Levinson agreed, saying that Libraries already have the infrastructure, the resources and the tools to not only preserve the data but to make it “findable” by the public.

“There’s 7 billion people in the world – most of whom don’t want to use my data – but a couple of whom might. And they might not know that the data exist” if it’s just sitting on my computer, he said. “Putting it out into a standardized, findable public forum makes it easier for them to: A) Know that the data exists; and B) Actually get at the data.”

Open Access Article: Spatial modeling of bicycle activity at signalized intersections | Institute of Transportation Studies Library

Open Access Article: Spatial modeling of bicycle activity at signalized intersections

Biking at Grand/Halsted/Milwaukee (3 of 4)

This week is Open Access Week. What’s Open Access? Here is a not very brief overview by Peter Suber. UC Berkeley also has an Open Access Initiative to help open up your research and data. 

In the spirit of Open Access Week, here’s an interesting article from an open access journal – The Journal of Transport and Land Use. Go check it out and peruse the articles. No need to depend on your institution’s sibscription because it’s free to the public! (Thanks open access!)

In “Spatial modeling of bicycle activity at signalized intersections“, Jillian Strauss and Luis F Miranda-Moreno look at the built-environment and cycling. 

This paper presents a methodology to investigate the link between bicycle activity and built environment, road and transit network characteristics, and bicycle facilities while also accounting for spatial autocorrelation between intersections. The methodology includes the normalization of manual cyclist counts to average seasonal daily volumes (ASDV), taking into account temporal variations and using hourly, daily, and monthly expansion factors obtained from automatic bicycle count data. To correct for weather conditions, two approaches were used. In the first approach, a relative weather ridership model was generated using the automatic bicycle count and weather data. In the second approach, weather variables were introduced directly into the model. For each approach, the effects of built environment, road and transit characteristics, and bicycle facilities on cyclist volumes were determined. It was found that employment, schools, metro stations, bus stops, parks, land mix, mean income, bicycle facility type (bicycle lanes and cycle tracks), length of bicycle facilities, average street length, and presence of parking entrances were associated with bicycle activity. From these, it was found that the main factors associated with bicycle activity were land-use mix, cycle track presence, and employment density. For instance, intersections with cycle tracks have on average 61 percent more cyclists than intersections without. An increase of 10 percent in land-use mix or employment density would cause an increase of 8 percent or 5.3 percent, respectively, in bicycle flows. The methods and results proposed in this research are helpful for planning bicycle facilities and analyzing cyclist safety. Limitations and future work are discussed at the end of this paper.

The full article can be found here

Black Holes: A brief treatise on the nature of journal publications and the conditions necessary for formation of black holes in networks of scholarly communication.

Academia should be faster than it is. This especially applies to the transportation and planning journals with which I am familiar. It often takes more than a year to do less than 8 hours of work (reviews and editorial decision-making).
Some peer reviewed journals (which will remain nameless in this post) are best described as Black Holes. Articles are submitted to be reviewed and never escape. There may or may not be an acknowledgment of receipt. The paper may or may not have been sent to reviewers. The reviewers may or may not have acknowledged receiving the paper in a timely fashion. They may or may not conduct the review in a timely fashion. Some reviewers might do their job, but the editor may be waiting on the slow reviewer before making a decision.
There are several causes for this black hole:

  1. Authors – Why would you be foolish enough to place your trust in an editor you don’t know? But of course, for graduate students and tenure track faculty, what choice do you have when your career is determined by success in the publication game? In this game, the author is in general the supplicant. If the author is famous, the situation might be reversed, and the editor should be seeking your paper to make their journal stronger, but given there are well over 1 million peer-reviewed journal articles published each year (and I guess 2x that submitted), and only 20,000 Scopus indexed journals, the average journal has leverage over the average author.
  2. Reviewers – Why would I do free labor for a stranger (the Editor) for a community I don’t know (prospective readers) to help an anonymous person (the Author)? Why would I do it quickly?
    • The noble answer is to stay on top of cutting edge research.
    • A plausible answer is the opportunity to ensure your own work is properly referenced. Though this might appear sketchy to you as an author when reviewers say cite X, Y, and Z (and reveal themselves), yet you as an author will still cite these works in the revised manuscript, and it looks perfectly natural to the reader. This motivates the reviewer and raises the citation rate of the reviewer’s own works.
    • Another answer is to accumulate social capital.
      Where exactly do I redeem the social capital I am accumulating? Where is the social capital bank:
      Editors write promotion (or immigration!) letters in support of good, quick, helpful reviewers. Editors might more favorably view the papers of helpful reviewers. Editors might more favorably review proposals of helpful reviewers. Editors might be more likely to nominate good reviewers for awards. Editors might nominate good reviewers to an Editorial Advisory Board and bestow upon them some prestige. The reviewer might be an editor elsewhere and be able to “return the favor”. But all of this is probabilistic and a bit vaporous. Journals sometimes publish list of reviewers. In any case, a list of (self-reported) number of reviews by journal is one of the beans that is counted in the promotion and tenure process.
  3. Editors – What leverage do I have over unpaid labor (reviewers) and why should I care personally about ungrateful authors who have submitted an unready paper to my journal which will almost inevitably not be accepted the first round. The leverage is future favors I might bestow in advancement of potential reviewers (see above). This indicates Editors should favor graduate students and assistant professors as reviewers over full professors. Unfortunately full professors are more famous and more likely to be selected to do reviews. I am personally running at a rate of about 100 review requests per year now. If I were really famous, I would need to decline far more than I do now. If I were really, really famous, I would not have time to decline requests (or perhaps I would have staff decline requests for me).

So there is a social network at play in this process, and if any link breaks between author and editor, between editor and reviewer, or back from reviewer to editor or editor to author, the circuit is not complete, the paper entered the system, and like a light from a black hole, cannot escape.
This is one reason I like journals that have check to automatically track publication status, nag reviewers, and have quick turnaround times. This is one reason I like the idea of “desk reject”. It is much better to be rejected immediately then after 6, 9, 18, 24 months of review. Fast has value.
There is a second black hole, not quite as large, dealing with accepted papers that have yet to be formatted for publication. This is usually solved by an online “articles in press” or “online first” section of the journal website. The advantage to the journal of this is the ability for papers to accumulate citations before they are actually “published”, thereby gaming the ISI impact factors, which look at the number of citations in the first 2 years from publication.
A major problem with looking at 2 years when journals are slow is apparent. I cite only papers published before I submit my paper. If it takes 2 years to accept and publish, I will not have included any papers from the past two years. Therefore slow fields have lower impact factors than fast fields. This feeds the notion (in a positive feedback way) that these fields are sleepy backwaters of scientific research rather than cutting edge fields where people care about progress.
To break the black holes I have a couple of ideas:

  1. A “name and shame” open database (or even a wiki) which tracks article submissions by journal, so that authors have a realistic assessment of review, and possibly re-review and publication times. Also the amount of time in the author’s hands for revision would be tracked.
  2. Money to pay reviewers and editors to act in a timely fashion and publication charges to finance open scholarly communication. A few journals pay reviewers. When I get one of those, I am far more likely to review quickly than when I get requests from other journals, especially for journals outside my core area, especially when the likelihood of withdrawing social capital is minimal. Other journals charge authors and use the funds to speed the process (but as far as I know these journals don’t pay reviewers). Of course, we need to be clear to avoid “pay to play”. Libraries could help here, redirecting funds from the traditional subscription model to a new open access model, helping their university’s authors publish in truly open access journals. The new federal initiative will hopefully tip the balance.

We all know the journal system as we have known it is unlike to survive as is for the next 100 years. It is surprising it is lasted as long as it has, but academia is one of the last guilds.
There are lots of cool models out there beyond the traditional library pays for subscription of expensive journal: from open access journals with sponsors (JTLU), author fees (PLOS_One), membership (PeerJ), decentralized archives (RePEc), and centralized electronic archives arXiv.
Yet we need some way of separating the wheat from the chaff, and peer-review, as imperfect as it is, has advantages over the open internet where any crank can write a blog post.
Eventually time will act as a filter, but peer-review, the review of papers by experts to filter out the poorly written, the wrong, the repetitive and the redundant, can save readers much time.



We have an entry in the Knight Foundation’s Knight News Challenge, which asks “How might we improve the way citizens and governments interact?”. Ours is OpenScheduleTracker. Please go there to read the details and “applaud”.

OpenScheduleTracker archives public transit schedules and provides an easy-to-use interface for understanding how schedules change over time, comparing different schedule versions, and identifying what areas are most affected by schedule changes.

What’s The Problem?

OpenScheduleTracker addresses three primary weaknesses in the way that transit system changes are currently reported and discussed:
1. Small changes are ignored
Public transit schedules evolve constantly, but we often focus only on big changes — new routes, new stations, line closures — and ignore small changes like schedule adjustments, frequency changes, and transfer synchronization. These small changes are not glamorous, but they can have a big impact on the way that a transit system meets or misses the needs of local communities.
2. Big changes are misunderstood
When a new bus route is added or a new rail station opens, the public discussion tends to focus on effects near the new facility: people want to know what’s happening “in my backyard.” These effects are important, but they are only part of the whole picture. Changes to transit systems have network effects which extend through the entire system: a new station in one neighborhood provides access to local opportunities for all users of the system.
3. Old schedules aren’t available for comparison
Analyzing schedule changes over time is often frustrated by the inconsistent availability of previous transit schedule versions. Transit operators’ policies for archiving historical schedule data varies widely, and even when schedules are archived the public often has access only to the current version. Public transit system schedules are significant investments of time, money, and expertise; when they are lost or inaccessible, the public loses the value of that investment.

FOSS4G: FOSS Experiences in Transportation and Land Use Research


Andrew Owen will represent the Nexus group at the FOSS4G (Free and Open Source Software
for Geospatial – North America 2013) conference happening in Minneapolis, May 22-24.

FOSS Experiences in Transportation and Land Use Research
Andrew Owen, University of Minnesota ­­ Nexus Research Group

The Nexus Research Group at the University of Minnesota focuses on understanding the intersections of transportation and land use. In this presentation, we will examine case studies of how open ­source geospatial software has fit into specific research projects. We will discuss why and how open­ source software was chosen, how it strengthened our research, what areas we see as most important for development, and offer suggestions for increasing the use of open­ source geospatial software in transportation and land use research. Over the past two years, we have begun incorporating open­ source geospatial data and analysis tools into a research workflow that had been dominated by commercial packages. Most significantly, we implemented an instance of OpenTripPlanner Analyst for calculation of transit travel time matrices, and deployed QGIS and PostGIS for data manipulation and analysis. The project achieved a completely open research workflow, though this brought both benefits and challenges. Strengths of open ­source software in this research context include cutting ­edge transit analysis tools, efficient parallel processing of large data sets, and default creation of open data formats. We hope that our experience will encourage research users to adopt open­ source geospatial research tools, and inspire developers to target enhancements that can specifically benefit research users.