News and Coverage

The Real Time City

City Tech
Location: Crystal Room Level: Intermediate
Average rating: **...
(2.00, 2 ratings)

The way we describe and understand cities is being radically transformed, alongside the tools we use to design them and impact on their physical structure. While architecture has shaped the built environment to satisfy urban dwellers aesthetically and to accommodate their functional needs such as face-to-face interactions and travel, pervasive systems shape electronically mediated interactions in urban space, including use of both fixed and mobile displays and wireless communication (see CityWare).

A major issue is space and its relationship with behavior: how do we design the ambient created by fusing electronically created interaction space with architecturally created physical space? Another major issue is infrastructure: how do we provide interaction and interoperability that scale up to city-level pervasive systems, while ensuring that they function appropriately and merge aesthetically with urban spaces, materials, forms, and uses?

At the SENSEable City Laboratory, a new research initiative at the Massachusetts Institute of Technology, our team of researchers explores the changes of the built environment through a cross-disciplinary approach that integrates urban studies, engineering, interaction design, and social studies. We try to answer questions like what will be the impact of pervasive and ubiquitous technologies on urban life itself? What will be the effects of the real-time feedback that will be enacted between people and the built environment? What type of new public services and business models could emerge, and how will current services and businesses be affected and transformed by the upcoming disruptions?

Building pervasive systems requires a new way of thinking about the design and use of ICT systems and how they interweave with the built environment. In urban areas we have the greatest opportunities and the strongest demands to design and build pervasive systems, yet urban design has not featured strongly in pervasive systems research. We have no fundamental theory, knowledge base, principled methods or tools for designing and building pervasive systems as integral elements of the urban landscape (see Eisenman 2006). We are interested in designing not just the architectural space in which people move, behave, and interact but also the interaction spaces for information and services which they discover and use and which support their movements, behaviors, and interactions within architectural space.

The combined effect of these innovations is monumental. For the first time ever, for instance, it is possible to visualize the dynamics of a whole city in real-time by monitoring cell phone traces (see WikiCity [Rome]) and to display the global patterns of telephone and Internet traffic between cities all around the world (see New York Talk Exchange). New services can be built, and old services like those provided by Yellow Pages can be strongly improved using geo-tagging, time-tagging, and review information added by companies and citizens themselves. For example, data could be provided to taxi companies to improve their service and to citizens to easily find an available cab; special events like concerts could be better organized and experienced by the community; new solutions to solve traffic jams and parking problems could be explored; interactive maps and other devices could be used to augment our senses in the city.


WikiCity is a multi-year research effort that started by developing a dynamic model of a city interpreted as a real-time, location-sensitive, non-stochastic control system which, drawing its foundations from classical control theory, can be optimized by enacting a feedback loop between people and places through technology. The project then evolved building on the research strings described above and started combining under one common vision the aspects of sensing, time- and location-based data structuring and input/output articulation within the context of urban environments. Today WikiCity is concerned with the real-time mapping of city dynamics which becomes a decision support system for the citizens, the businesses, and the authorities to base their actions in a better informed manner. In this way the real-time map changes the city context as well as that altered context changes the real-time map accordingly, with the ultimate aim of leading to an overall increased efficiency of the city environment.

A diffused social consciousness regarding urban dynamics can improve mobility patterns, which will benefit the sustainability of our built environment. The understanding and visualization of these flows allow us to give city-users immediate and clear feedback about how their city functions. Dynamic events can be represented by organized, official happenings at the city level, such as festivals and carnivals. Our project called WikiCity [Rome] (2007) analyzed the Notte Bianca, an all-night festival that hosts artistic performances at various locations throughout the city. We collected real-time data based on cell-phone usage, and projected the information live on a public screen during the event as well as in a post-event online version.

We investigate not only special events, but also everyday happenings and the unexpected episodes that divert from the usual activities recorded in the city. The capillary presence of diffused technologies in the city allows us to reveal various flows and clustering mobility patterns. With a better understanding of traffic flows, we can define smarter guidelines for a more sustainable mobility. This was the main objective of the RealTime Rome project in 2006, where data aggregated from cell-phones, buses and taxis were used to interpret the pulse of the city, thus showing how technology can help individuals make more informed decisions about their environment and optimize their impact concerning mobility patterns.


New York Talk Exchange illustrates the global exchange of information in real time by visualizing volumes of long distance telephone and IP (Internet Protocol) data flowing between New York and cities around the world. In an information age, telecommunications such as the Internet and the telephone bind people across space by eviscerating the constraints of distance. To reveal the relationships that New Yorkers have with the rest of the world, New York Talk Exchange asks: How does the city of New York connect to other cities? With which cities does New York have the strongest ties and how do these relationships shift with time? How does the rest of the world reach into the neighborhoods of New York?

The project illustrates how different parts of the city are linked to very different portions of the planet. For example, Mumbai, India, ranks 24th as the origin of calls into Manhattan, and 11th in calls into Queens. Toronto, Canada, is one of the main destinations for calls out of Manhattan, but accounts for only 1 percent of calls from the Bronx. As Columbia University Professor Saskia Sassen, author of the book “Global Cities,” details in the NYTE project catalog, “The striking piece of evidence coming out of this project is that global talk happens both at the top of the economy and at its lower end. The vast middle layers of our society are far less global; the middle talks mostly nationally and locally.”


Raster Cities represents a new paradigm for assessing the environment consequences of urban texture. This new approach is based on the use of simple raster models of cities, called Digital Elevation Models (DEMs). Using software algorithms derived from image processing it is possible to develop efficient methods of measuring geometric parameters and assessing radiation exchange, energy consumption, wind porosity, etc. Results are extremely fast and accurate; due to the increasing availability of DEMs from lidar, they could open the way to new raster-based urban models for planning and design.

This is centred on the relationship existing between environmental indicators and urban morphology: the question is if – and in what measure – the correct arrangement and the shape of the urban fabric alone might improve the environmental behavior of the city. With the aim of creating effective environmental quality starting just from morphology, several design tools can be developed, assessing new potentialities related to the form of human settlements. For instance, the energy-based morphogenesis of the built environment could be intended as the first step towards the improvement of the sustainability of cities with no additional cost due to the application of complex technologies.

The tools reveal themselves to be a feasible way to assess the environmental quality of urban spaces. Under the broad definition of environmental quality, aspects related to both energy efficiency and human comfort are taken into account: on the one hand, the aim is to quantify the potential energy efficiency derived from the capacity of the urban fabric to take advantage of passive gains at the city scale; on the other hand, aspects of perceived comfort in urban open spaces are investigated, among others or through visual preference analyses, through the definition of thermal conditions. Environmental parameters include solar access (solar paths, mean shadow density, solar gain through solar envelopes, sky-view factors), energy consumption (surface-to-volume ratio and passive/non-passive zones), cross-ventilation, wind porosity, urban canyon height-to-width, pedestrian accessibility and visual perception of open spaces through isovist fields.


The large deployment of mobile devices has led to a massive increase in the volume of records of where people have been and when they were there. The emergence and the novel access to these digital footprints coming from the “virtual world” is expected to have significant impact on urban and social studies and by consequence on tourism studies. One type of digital footprints comes from people’s implicit interaction with infrastructures which results, for instance, in location logs produced when carrying a mobile phone which is in constant dialogue with a wireless network. In addition to these automatically generated and implicit data, another type is generated explicitly by mobile and web users when they publicly disclose content such as photos, messages, sensor measurements or blog posts.

In this case study that quantifies the impact of the Waterfalls public exhibit in New York City, we designed and implemented a cellphone activity monitoring system, based on cell statistics like the number of calls and SMS related to the cell sectors covering each vantage points. With the contribution of traditional survey techniques such as field counts to calibrate these mobile phone network measures, we developed techniques to estimate over time and space the number of tourists. In addition, using eigenvector analysis and clustering techniques, it is possible to identify areas with similar characteristics: we have termed them eigenplaces, and they can represent spaces such as residential areas, recreational zones, and nodes of traffic and flow.

Photo of Andrea Vaccari

Andrea Vaccari

Senseable City Lab, MIT

Andrea Vaccari is research assistant at the Senseable City Lab of the Massachusetts Institute of Technology where he is studying the integration of information and communication technologies in the built environment, and their implications in the social dynamics that drive city life itself. Throughout initiatives like WikiCity and the New York Talk Exchange, currently featured at the Museum of Modern Art in New York, the laboratory aims to leverage the huge volume of real-time geo-referenced data provided by digital devices and sensor networks to better understand cities as real-time control systems, and to provide new tools to innovate and anticipate the effects of such innovations. Vaccari is currently completing his M.Sc. in computer engineering at the Politecnico di Milano, Italy and the joint program in computer science at the University of Illinois at Chicago.

  • Sun Microsystems
  • Yahoo! Inc.
  • IEEE
  • Make magazine
  • Orange Labs