Live Singapore: Raining Taxis

Singapore's mobility is heavily reliant on taxis, but what happens when it rains? This visualization explores how Singapore's transportation system behaves by combining taxi and rainfall data, and investigating how in the future the system can be streamlined in order to better match taxi supply and demand.

My role on this project was designing and developing the visualization. The data we received comes from Comfort DelGro; the largest taxi company in Singapore. Each of their taxis is fitted with a computer which tracks it's position via GPS transmitting a new status report roughly every 30 seconds. The computer keeps track of the taxi status if it's free, on-call, passenger on board, the driver is busy or on break, or offline. The application focuses on three taxi states; available taxis, on-call taxis, and the point at which a taxi picks up a passenger. As the available taxis movie around their route is represented by green lines, while the on-call taxi routes are represented by orange lines. When a taxi picks up a passenger, a yellow circle flashes briefly at that location. At any given time there are between 4,000 and 10,000 taxis in the data set being represented.

In addition to the taxi data, we are visualizing rain activity. We received rain density measurements from a radar system located near Changi Airport, displaying the intensity of rain activity around the island. The images are analyzed and represented as voxel clouds, where the more densely raining areas are portrayed as thicker, more opaque voxel clouds. The combination of rain activity and taxi driver activity is interesting to see, as taxi demand increases with rain and driver availability decreases.

The project is part of an exhibition featured at the Singapore Art Museum from April 7th to May 1st, 2011, as well as the Marina Bay City Gallery from April 14th to May 14th, 2011. The project was developed by the MIT SENSEable City Laboratory in conjunction with the Singapore-MIT Alliance for Research and Technology.