Lisbon's Traffic - Blood Vessels

Pedro M Cruz has updated his work on the Lisboa traffic visualisation. His earlier visualisation, part of his Master Thesis, featured here and on many other blogs back in April 2010.

The visualisations are built in processing using different models. The data represented traffic on the roads of Lisbon recorded over the period of one month.

About his new version Cruz sais: "the traffic of Lisbon is portrayed exploring metaphors of living organisms with circulatory problems. Rather than being an aesthetic essay or a set of decorative artifacts, my approach focuses on synthesizing and conveying meaning through data portrayal".

His new attempt is clearly chalenging to some extend slowly settling standards in the field of visualisation. Those being the attempt to visualise everything as is and as much of it as possible. Traditional techniques of abstraction, simplification or focus, what ever you would like to call it, are ignored and rendered away using sheer computing power.

The system used here is developed having some rough biology concepts in mind, images of blood vessels. Cruze explains: "the thickness, the color and the length of the vessels are excited by the number of vehicles and average velocity in each road".


Image taken from mondeguinho.com / The road network of Lisbon was queried from OpenSreetMap, parsed and filtered. Using this information, a spring based physics system is build for the road network and a filling structure of each vessel. The data is overlaid on the resultant structure to determine the road where each vehicle is at a given moment. This allows to inject data at runtime and excite the system.

This has a dramatic effect for the representation of the geometry and alters the appearance of the whole system. Nevertheless since the visualisation is reduced to the road as the single feature this is not producing any complication, on the contrary the system starts to become readable.

Especially interesting in this visualisation is the built in time-distance representation. The basic idea of that if a connection is fast it is short and if it is slow it becomes longer. This is as if saying time = distance (length). This is of course a very abstract and dangerous thing to propose, but in this case it produces some interesting results, since one all of a sudden is reading a visualisation roughly to its location in regards of how long it takes. As Cruz points out his is connecting the local and the global features of this representation and in this sense take it a step forward. Details on his blog.

Lisbon Traffic Visualised

For his Masters Thesis, Pedro Cruz has developed a visualisation of Lisbon traffic. It represents 24 hours in the capital of Portugal.
The data is derived from 1534 vehicles recorded over one month. All the records are then put into a 24 hour stack.
The colours represent the speed of the traffic with green being fast and orange/red being slower. The main roads to bring traffic through the city with a higher speed show up in green where as the local roads beautifully draw the tight network in between.


Image by Pedro Cruz / Vehicule traffic in Lisbon on a Friday, visulisation inspired by Aron Koblins's flight patterns.

The visualisations are built in processing and Cruz experimented with a number of different typs, each emphasising a different aspect. He eventually settled for one that is combining the speed as well as the focus on the main road. I am not sure however what the trailings/diagonals, between points actually mean. Guess it could be were the tracking signal was ost, but that seems a bit too geometrical for this. On the other hand as an area it also doesn't make too much sense. Cruz describes it as a visual thing.
Interestingly the speed on the local roads seems to be fairly constant, were as the speed on the main roads seems to slow down at night. This is surprising, since one would think that during the day there is more traffic and drivers would naturally slow down or even get slowed down by clunked up roads. on the other hand, at night there is more room on these roads and drivers would go faster and race around the city.
However this is great visualisation work. For more such visualisation visit Cruz's blog or his vimeo channel.



Found via Datavisulisation.ch .