Estimation of travel time and distance between communes in Poland in 2021
A A AThe matrix of accessibility was first published in 2019. It contains estimated distances and travel times between selected communes in Poland as at the end of 2016. The following matrix of accessibility is based on data representing the situation on the census day, i.e. March 31, 2021.
As in the case of the matrix based on data for 2016, all communes are represented by their centroids, which were calculated using the gCentroid() function from the rgeos R package.
Given the purpose of the matrix and the commonly accepted approach, a centroid is defined as a given commune’s centre of mass provided this point is situated within the borders of that commune (true centroid). In cases when the centre of mass was located outside the commune’s area, a point closest to the centre of mass was chosen for the analysis. Some centroids identified in this way had to be additionally modified in order to link their locations with road accessibility. For example, such corrections were required when centroids were located within a military training ground, a national park, a water reservoir, a mountainous area, near a location with temporary transport disruptions (e.g. related to road construction).
In comparison to the matrix published in 2019, two modifications have been introduced in response to the demand reported by data users. Firstly, the new matrix contains all pairs of communes in Poland (including urban and rural parts of urban-rural communes) rather than only those where work-related population flows were recorded. Secondly, the matrix now contains geographical coordinates of commune centroids (longitude, latitude) according to World Geodetic System '84 (WGS84).
Any questions relating to the matrix can be sent to Anna Stępniak from the Centre for Urban Statistics at the Statistical Office in Poznan, at A.Stepniak@stat.gov.pl, phone number: 612798324