Average annual rate of change in the number of heavy truck vehicles on the state roads of the Republic of Serbia

The traffic flow structure consists of different types of vehicles. The data taken in the process of the pavement design, which indicates the type of vehicle, is called AADT. AADT is the average annual daily traffic. The same AADT value can result in a different thickness of pavement, which is reflected in a different percentage of certain types of vehicles. For the traffic load design according to standard SRPS U.C4.010, it is important to know the rate of change in the number of heavy truck vehicles. The average annual rate of change in the number of heavy truck vehicles is used in design of the load. An analysis of the change in the number of heavy truck vehicles has been made for state roads in Serbia where traffic is counted. The paper presents an overview of the method of counting traffic on state roads. The average percent change in the number of heavy truck vehicles in the period 2014-2017 was analyzed.