Andrea Kovačević

Large retail developments act as strong trip attractors and can substantially alter traffic demand patterns at adjacent urban intersections. This paper analyzes the operational impacts of a major shopping center on two nearby signalized intersections in Novi Sad, Serbia, and evaluates the effects of reconstructing one of them into a turbo roundabout. Traffic data collected before and after the shopping center opening, as well as before and after the intersection reconstruction, were analyzed using calibrated and validated microsimulation models. Results indicate that peak-hour traffic volumes increased by 8.38% and 6.96% at the analyzed intersections following the shopping center opening, leading to increased delays and operational stress under fixed signal control, particularly under unbalanced turning demands. The conversion of the three-leg signalized intersection into a turbo roundabout resulted in substantial reductions in average delay and improvements in level of service under identical traffic demand conditions, mainly due to the elimination of left-turn signal phases and reduced conflict interactions. The findings confirm that turbo roundabouts can provide significant operational benefits in dense urban environments characterized by strong directional flows; however, their effectiveness is highly context-dependent and influenced by traffic composition and geometric constraints. The results are interpreted as representative of typical weekday peak conditions, acknowledging data and temporal limitations.

Shopping centers are significant traffic generators that influence traffic conditions on adjacent road networks. This study evaluates the impact of the Big Fashion shopping center in Novi Sad, Serbia, on two nearby signalized intersections and examines the effectiveness of reconstructing one of them into a turbo roundabout. Traffic counts conducted before (2015) and after (2020) the opening of the shopping center indicate notable increases in peak-hour traffic volumes: 8.38% at the Bulevar cara Lazara–Bulevar oslobođenja intersection and 6.96% at the Bulevar cara Lazara–Fruškogorska Street intersection. The increased demand contributed to higher delays and deteriorated levels of service. In 2023, the latter intersection was reconstructed into the region’s first turbo roundabout. Microsimulation (Synchro 11) using pre-reconstruction volumes revealed substantial operational improvements, including a reduction in the most critical left-turn delay from 165.5 s/veh to 11.9 s/veh. The results confirm that turbo roundabouts can effectively mitigate congestion and enhance intersection performance in urban environments with high directional turning movements.