Following the military occupation of Germany in May 1945, civilians were initially only allowed to leave their place of residence or its immediate vicinity with a permit from the garrison authority of their zone.
Nevertheless, there were numerous travelers who crossed the extensive uncontrolled boundaries between the garrison zones on foot, by bicycle or by hitch-hiking.
The Soviet military administration in Germany (SMAD) had previously asked the Allies to secure the line of demarcation to the Western zones.
As of November 14, 1953, the Federal Republic of Germany agreed with the Western Allies to abandon boundary inspection controls for inter-zone traffic.
Because the single express train route in inter-zonal traffic (FD 111/112) between Cologne and Berlin was permanently overburdened, five additional express train routes started to run over the German domestic boundary on September 10, 1949: On August 25, 1946, an inter-zones bus connection was opened between Berlin and Hanover.