The unique feature of this project is the 3 km double-deck motorway within the stormwater tunnel. The operation of the SMART system works on the three- principle mode of operation based on the flood discharge at the Klang River/ Ampang River confluence and the operation status of the motorway.

The first mode, under normal condition where there is no storm or low rainfall, no flood water will be diverted into the system.Under the second mode, SMART system will be activated and this happens when there is moderate storm.

When the second mode is activated, flood water is diverted into the bypass tunnel in the lower channel of the motorway tunnel and it is important to note, that, up to this stage, the motorway section is still open to traffic.

At the third mode of operation the motorway will be closed to traffic. With extensive and effective monitoring stations, when the third mode of operation is needed, the motorway will be closed to traffic. Sufficient time will be allocated to allow the last vehicle to exit the motorway before the automated water-tight gates are opened to allow flood water to pass through. The motorway will be reopened to traffic within 48 hours after the closure.

Tunnel Safety
Ventilation/ escape shafts at 1km intervals: these powerful air ventilators will constantly renew the air and maintain the air quality within the motorway. To protect the ventilation system during the flooding, the systems consist of a series of shafts each containing an exhaust and fresh air injector. This design enables the fans to be situated outside the SMART tunnel to create a longitudinal flow in the tunnel between the shafts that permits the air in the tunnel to be continuously renewed and to enable extraction of the exhaust fumes. The feature also allows for smoke control in the event of a fire.

Equipped with fire fighting, telecommunication and surveillance equipment at 1 km interval.