Studies had indicated that the critical stretch of Sungai Klang between Sg Klang /Sg Ampang confluence and Sg Gombak/ Sg Klang confluence to be flood prone areas and the fact that the river is further constrained by the Jalan Tun Perak Bridge (near Masjid Jamek) which is low, has resulted in the surrounding areas to experience flash floods.

The SMART system will be able to divert large volumes of flood water from entering this critical stretch via a holding pond, bypass tunnel and storage reservoir. This will reduce the flood water level at the Jalan Tun Perak Bridge, preventing spillover.

The Stormwater Management and Road Tunnel (SMART) project was incepted by the project proponent, namely MMC Berhad-Gamuda Berhad Joint Venture, primarily to mitigate the recurring floods in the city of Kuala Lumpur, the financial, business and commercial hub of Malaysia. However, at the design stage of SMART, the dual purpose concept was born from the ingenuity of the project proponents and the motorway tunnel was integrated into the system to relieve traffic congestion at the main Southern Gateway to the city centre.

The Motorway to Ease Congestion
The motorway tunnel will provide an alternative route for motorists from the Southern Gateway, i.e. KL-Seremban Highway, Federal Highway, Besraya and East-West Link entering and exiting the city centre. This will reduce traffic congestion at the Southern Gateway leading to the city centre. The travel time will be reduced
significantly. For example from the Jalan Istana Interchange-Kampung Pandan the expected travel time is a mere four minutes compared to ten to fifteen minutes using the existing roads.