The construction of the road from Kranjska Gora across the pass of Vršič (1,611 m) to Trenta began in the beginning of May 1915, when it was already clear that Italy was going to declare war on Austria-Hungary. 12,000 Russian POWs captured on the Eastern Front were transported to the site in order to build the road, which required superhuman efforts. They were lodged in simple cabins, ill fed and poorly dressed. Many of them died from exhaustion and diseases. The road served to supply the Austro-Hungarian troops on the Isonzo Front and to transport the wounded from the front. It was already being used for transport at the end of 1915.
The army did not listen to the warnings from local people about the serious threat of avalanches during winter time, because they were convinced they could avoid the disaster by building wooden galleries that the avalanches would just pass by. Unfortunately, this was not the case. Due to the great amounts of snow, avalanches started to trigger on the slopes of Mt. Mojstrovka in March 1916, taking with them everything in their path, builders of the road, galleries and cable ways. Because of frequent avalanches the route of the road had to be changed on some points.
Between both Wars, the northern part of the Vršič Road was under the reign of the Kingdom of Yugoslavia and the southern part under Italian rule. The border line ran over the Vršič Pass.
The entrance and the exit of the tunnel is located on the side of the Trenta Valley, roughly 2 kilometres below the Vršič Pass.