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Pocket City: an interactive urban planning tool

A flurry of construction projects in China in recent years has challenged urban planners and designers, creating an urgent need for smart urban planning and design tools. In response, Arup has developed Pocket City, an interactive urban planning tool that combines multidisciplinary data into one interactive platform for early stage urban planning and design visualisation.

Pocket City uses VisSIM™ and MassMotion™ (an Oasys software tool developed by Arup) in conjunction with the Unity3D™ platform, microclimate analysis and GIS (geographical information system) supported by multidisciplinary input from planning, urban design, transportation, landscape architecture and building physics. The resulting tool is intuitive, easy-to-use, interactive, portable and reactive. Unlike an ordinary visualisation tool, Pocket City can quickly analyse multiple design scenarios and complex algorithms. Crowd simulation enables urban planners to define different waypoints for destinations and spawn points for crowd populations. Traffic system simulation includes a traffic signal system that controls all vehicles to simulate real-life vehicle behaviours. The GIS capability reads online map data and imports terrain and map colours into the model.

Instead of a hypothetical environment, Pocket City shows a working model of the behaviour of a city. Users can ‘fly’ through the city. They can zoom in on any detail to show a 3D simulated environment that displays the complex interaction between the physical environment, pedestrian behaviour and traffic. Instead of revising design schemes back at the office, planners and clients can change the physical properties via a tablet, and instantly see the results.

Quantitative and visual methods can enhance urban planning processes and add value to the quality of multidisciplinary designs.

The team applied Pocket City to a transit-oriented development project in southern China. We built a pedestrian behaviour model to simulate passenger dispersion from a metro station to their destinations, and overlaid microclimate data to evaluate the impact of thermal comfort on pedestrian movements.  Nuanced behaviours and effects can be modelled.  For example, the results showed that unless the public spaces were well shaded during the morning and midday hours, pedestrian movements would be limited to certain areas only, and businesses elsewhere around the station would suffer from low visitor retention rates. The design was then adjusted to include green cover at strategic locations, reducing temperatures, and encouraging pedestrian movement to be more evenly distributed.

Pocket City enables urban planning projects to become opportunities for better integrated, total design, extending detailed behavioural analysis to large-scale design decisions.

Urban planners can integrate Pocket City in their design workflow, create complex algorithms for behaviour design of traffic and pedestrians, and encourage the multidisciplinary design process through visualization of scenarios between planners, designers, and engineers.


Pocket City is the first tool of its kind for urban planning and design.

By integrating different emerging technologies, including augmented reality, tangible interfaces and virtual reality, Pocket City models design solutions so that users can ‘touch’, see and control them.  Urban planners, engineers and clients will be able to experience and understand an unbuilt project through a simulated environment.

By incorporating Pocket City and microclimate analysis, urban planners and designers can give early consideration to the effects of thermal comfort, and incorporate heat resilience into their designs.