The total length of bus lines. The length of the bus line is a length of the route, expressed in km, between two extreme localities, regardless of the number of bus drives (according to the bus time table) on this line.

The bus lines are split into: - urban lines (lines in urban areas that can occasionally cross urban boundaries to the nearest gravitational area of 5 to 10 km length), - suburban lines (lines in the boundaries of 50-60 km that link rural areas with gmina, powiat, and voivodeship centres), - regional lines (lines in the boundaries from 50-60 km to 160 km that link gmina centres and smaller cities with more important urban-industrial centres of the region), - long-distance lines (lines that cover the area of two or more regions, link voivodeship cities and more important industrial centres, culture centres, and tourist/health resort centres with big urban-industrial agglomerations of the country), - international lines (lines that cross the state borders).