Reversible Lane Control
Changing the direction of the middle traffic lane.
Changing the direction of the middle lane increases capacity in the direction with the higher traffic demand, where there is no room to widen the road by adding two or more lanes. Overhead signal displays, vehicle detection and a central control unit, connected to monitoring software, switch the middle lane between directions.

How the middle lane changes direction
Four successive states of the lane signals. In each state, the row for direction A and the row for direction B show one signal for the left, middle and right lane.
2Leaving the middle lane
3Middle lane closed in both directions
4Middle lane for direction A
Red crossed lines
No passage for vehicles facing the sign.
Green downward arrow
Passage allowed for vehicles facing the sign.
Flashing yellow arrow
A diagonal downward arrow means the lane must be left in the direction shown.
Serbian Rulebook on Traffic Signalling, Article 75, paragraphs 3–5.
Control and monitoring
Signal displays, vehicle detection and a central control unit, connected to monitoring software.
- Primary communication
- Fibre-optic link
- Backup communication
- 4G LTE
- Primary power supply
- 220 V AC mains
- Backup power supply
- UPS
Measured benefit — Teodora Drajzera Street
Share of the middle lane in the total daily flow of each direction.
24-hour count at the central portal of the section.
Systems installed in Belgrade
- Teodora Drajzera Street — 11 portals
- Bulevar kneza Aleksandra Karađorđevića — 7 portals
- Bulevar vojvode Mišića — 4 portals
- Tošin bunar — 5 portals
Total installed: 162 signal displays
Tošin bunar: before and after







