The Tomačevo roundabout in Ljubljana is the largest roundabout in Slovenia and the only one with traffic light control. The traffic flow capacity of the former three-leg roundabout had been inadequate for years.

Thus, the roundabout posed a true bottleneck at a vital traffic node, resulting in congestions exceeding a kilometre and a half in length. With the construction of a sports and shopping centre immediately next to the roundabout, reconstruction of the roundabout became urgent. Due to the vicinity of the largest Slovenian sports centre, the traffic volume has increased even further. Accordingly, the Tomačevo roundabout has been widened and traffic light control has been implemented.

Iskra Sistemi adapted the operation of the traffic lights to the traffic loads in individual roundabout legs. The traffic is monitored by 76 detector loops and the data on the number of vehicles and their gaps, as well as on any vehicle hold-ups along the incoming legs from the northern Ljubljana bypass to the traffic light control system. The duration of green traffic light periods is thus optimally adapted to the actual traffic loads. The roundabout is controlled by 44 three-part traffic light signal generators interlinked within a traffic light control system, and the latter is linked, through an optical link, to the automatic traffic control centre in Ljubljana and the DARS control centre at Dragomelj.