Before 1952, the inner German border could be crossed at almost any point along its length. The fortification of the border resulted in the severing of 32 railway lines, three autobahns, 31 main roads, eight primary roads, about 60 secondary roads and thousands of lanes and cart tracks.[105] The number of crossing points was reduced to three air corridors, three road corridors, two railway lines and two river connections giving transit access to Berlin, plus a handful of additional crossing points for freight traffic.[106]