The main goal in traffic is to get in the shortest possible time and with the utmost security going some way. There is a significant role for roads and accommodation, and this is affected by the relief. Observing the Republic of Croatia there are numerous obstacles in the form of smaller or larger hills. Therefore, in order to shorten the route, there is a need for tunneling. The construction of the tunnel is not a simple and secure job, and only recently, with the development of modern construction machinery, the tunnel construction intensified. Roadtunnels, because of the specificity of driving through them, must be secure not only from a construction standpoint but also from a traffic standpoint. This is achieved by incorporating a legally prescribed equipment and constant traffic control so that in the event of a crash it can react as quickly as possible. Attention to the public is very often directed to world's large tunnels, but small, "local" tunnels are of great importance in everyday migration of the population. One such tunnel is the tunnel "Ploča", whose construction has markedly shortened the road from the north and north-eastern part of Šibenik-Knin County to Šibenik.