by Pedro Miguel Cruz
This work constitutes several visual experiments that map the GPS coordinates and velocity of 1,534 vehicles circulating in Lisbon during October 2009. That information is condensed in one single virtual day, grouping the data by second and displaying it as an animation. Each experiment explores a different way to visualise and express information. These artifacts comprehend different snapshots of the traffic in Lisbon during one virtual day. Each image refers to the first second of the indicated hour.
(1) Red circles are drawn with a small opacity when the speed of the vehicles is inferior to 50 kilometres per hour. The radius of the circles is inversely proportional to the speed of the referring vehicle. The overall feel of the artifact seems to traduce an organism with circulatory problems.
(2) The trails of the vehicles group themselves into main arteries where the thickness represents traffic intensity during the day. Each trail constitutes a temporary route where the average speed is mapped to its colour. Pure green represents average speeds of 50 kilometres per hour. Therefore cooler and greenish hues traduce rapid transit arteries, while the sluggish ones are reddish and hotter. With this approach it is possible to visualise the evolution of the traffic speed and intensity in the main arteries and areas of the city.
(3) Each trail represents a temporary route, where the covered area is coloured in a pale gray. The covered area is defined by closing the route, connecting its origin and destination points. This representation scheme permits to emphasise the areas with more traffic, darker ones. Nevertheless, this is an aesthetics’ driven artifact, worthy by its complexity and expressiveness: pollution analogy, pencil and paper.
(4) The white dots are the circulating vehicles at that moment. The trails of the vehicles group themselves into main arteries where the thickness represents traffic intensity. Each trail constitutes a temporary route where the average speed is mapped to its colour. Pure green represents average speeds of 60 kilometres per hour. Therefore cooler and greenish hues traduce rapid transit arteries, while the sluggish ones are reddish and hotter. There is a visual emphasis on the slower areas, with hot colors traducing sluggish traffic.
