Santiago metro is one of the main transportation system for its 6.5 millions inhabitants. A data visualization of the average daily traffic density in Santiago metro, made by Data Publica and Inria Chile, helps understand better how the daily traffic is organized in Santiago.
This is an interactive data visualization (Dataviz) showing the traffic in Santiago metro of an average working day, for each half-an-hour of the day. The traffic density is measured by the number of people getting in the metro. The data was found on the Chilean governmentâ€™s Open Data portal: datos.gob.cl.
It shows where passengers come from, regardless of where theyâ€™re going and what connections they could have made during their trip. The size of a circle is proportionate to the number of people getting in the corresponding station, and the ranking buttons add up all the data of the day/morning/afternoon.
As expected, more entries into the metro have been registered in areas with a high density of corporations or universitary zones: Santiago Centro, Providencia, Las Condes. However, the station registering the most entries is surprisingly a station far from the center: La Cisterna, with an average of 74.133 entries a day.
The only data available to measure the traffic density is the number of people entering in each station, which had originally been published by the Subsecretary to Transports (a department of the Chilean Transport and Telecommunication Ministry). A lot of interesting data is still missing, for instance the number of people getting out a station, the number of combinations in main hubs (like Baquedano), the number of people taking a bus before or after taking the metro, etc.
To estimate the number of people getting in a specific metro station, the Ministry used a Origin-to-Destination Matrix of working day trips built up by the Universidad de Chile. The sample was taken in a regular working week (Monday to Friday) of April 2012.
To estimate the average number of entries for each half-an-hour, data of every day of the week was added and then divided by 5, the total number of working days a week.
The Ministry of Transportâ€™s datasets were combined with the following one: Feed GTFS de Transantiago, in order to have the geographical position of each station. The geographical coordinates of the whole Santiago zone were obtained here.
Thanks to the map, and especially the sum of passengers during the day/afternoon/morning, it is possible to identify residential areas (more passengers in the morning) and working districts (more passengers in the afternoon). The traffic density is indeed higher in business districts such as Santiago Centro (Universidad de Chile and Los HÃ©roes stations) and Providencia/Las Condes (Tobalaba, Pedro de Valdivia, Escuela Militar, Manquehue stations). The traffic density is also lower in the other districts of Santiago, for they are mainly residential.
It is also a tool to identify some unexpected hubs. For instance, La Cisterna station is rather far from the center, but it is still registering the most important number of entries of the whole metro system! It can be concluded that it is a hub within an important bus network, covering the whole south-eastern part of Santiago.
This article has been translated by its author Louis Leclerc from Spanish into English. The original article in Spanish can be found here.