In the capacity analysis of roundabouts, correctly determining of the degree of saturation and control delay is of the highest importance, because these parameters are the main indicators of traffic flow quality. This paper briefly describes models of compute control delay on roundabouts that are currently most widely used in practice, such as: HCM, Akcelik, Brilon. In conclusion, will be recommended the guidelines for calibration process of these methods.

After completion of the first phase of the project of general overhaul main repair of the railway line from the state border (Capljina) to Bradina, in the Federation B&H, a general overhaul from Bradina to Sarajevo, in total length of 36 km, currently is in progress. Implementation of Phase II of this project will be completed general overhaul of whole so-called south line from Capljina to Sarajevo. General overhaul of railroad includes replacement of superstructure elements, while a just few works consider improving the substructure, structures (bridges, tunnels) and technical elements (radius of curves and etc.). This paper will give an overview of line condition before and after the general overhaul implemented, and effects of this way of implementation of the general overhaul in terms of increasing speed and traffic safety.

The continuous welded rail is now in widespread use on most railways. The main reasons for their mass deployment is in the numerous advantages over the jointed track (in technical, environmental and economic terms), as well as being one of the basic preconditions for the introduction of high speed services. The main disadvantage of continuously welded tracks is reflected in the limited freedom of expansion and contraction of the rails due to temperature changes. As a consequence, large longitudinal forces induced in the rails lead to rail deformation and lateral and longitudinal displacements of the track. This paper will present a methodology for ensuring stability in the CWR track (leaflet UI C 720), and will make its comparison with the calculation method of the CWR track defined in the applicable regulations, on the lines in operation in Bosnia and Herzegovina.