AN EVALUATION OF TURBO ROUNDABOUT PERFORMANCES: CASE STUDY OF THE CITY OF OHRID

Abstract

The turbo roundabout is an innovative design of the two lane roundabout that has revolutionised roundabout design. According to the international research, it is determined that the turbo roundabout has a higher level of traffic safety because of the lower number of conflicts and the use of raised lane dividers. In addition, compared with the conventional two lane roundabout, turbo roundabout has higher capacity. Due to these advantages, the reconstruction of intersections into turbo roundabouts has become a kind of global trend nowadays. The first turbo roundabout in the Republic of Macedonia was designed in Skopje in 2011, without tracking the performances. This was exactly the motive to investigate the performances of this type of intersections. In this research three intersections in sequence located in Ohrid (two signalized and one non-signalized intersection) and the performances are determined for the current situation and the situation with increased flows by using the software tool SIDRA. A reconstruction of the intersections has been made into turbo roundabouts. The performances for two different cases (current situation and the situation with increased flows, with and without the pedestrians’ influence) are determined with the use of both VISSIM and analytical model by Brilon and Wu. The analysis has proven that with the input parameters, turbo roundabouts offer better performances compared to the existing intersections. Thus, the reconstruction of the intersections is justified.