The North–South Expressway Southern Route is an interstate controlled-access highway running parallel to the southwestern coast of Peninsular Malaysia. The expressway forms the south section of the North–South Expressway, connecting the states of Selangor, Negeri Sembilan, Malacca and Johor. It begins at Seri Kembangan, near the state/territory boundary between Selangor and Kuala Lumpur and travels southwards to end at Pandan-Tebrau in Johor. The expressway is the third longest in Peninsular Malaysia, after its northern counterpart and the East Coast Expressway. The Kilometre Zero of the entire expressway is located at the Pandan Interchange with the Johor Bahru Eastern Dispersal Link Expressway. Route background Sungai Besi to Nilai North The expressway begins at the Sungai Besi toll plaza. The Kuala Lumpur–Seremban Expressway links Sungai Besi toll plaza to Jalan Istana and the Besraya Expressway near the Sungai Besi RMAF base. This section is a six-lane carriageway. This section serve the southwestern part of Klang Valley, passing by a few major towns. The expressway connect to Universiti Putra Malaysia via UPM Interchange, which also provide connection to nearby other suburban towns like Seri Kembangan via Besraya and Putrajaya via SKVE as well as Universiti Tenaga Nasional (UNITEN) nearby. Kajang interchange however is an interchange with Kajang SILK E18 on their Country Heights Interchange, before connecting it to Kajang town and the rest of E18 network. Bangi Interchange connects to Bandar Baru Bangi township and National University of Malaysia (UKM). Newly build Southville City Interchange links to Federal Route 31 (Banting-Kajang Route) which provide access to Dengkil and Semenyih after passing the Southville City new developments. Putra Mahkota, the last interchange of the Selangor part of the route, connects to Bandar Seri Putra housing developments. The state border of Selangor-Negeri Sembilan follows after. This section only has laybys on Serdang and Nilai, with Nilai southbound also provide access to Nilai Memorial Park. However what makes them different from other laybys is the food stalls building is also present in these laybys, which makes their function similar to rest areas. Nilai North to Seremban From this point the expressway enters Negeri Sembilan, running southwesterly towards Nilai. The interchange to ELITE E6 lies in the northern part of Nilai, near the Selangor–Negeri Sembilan border, enabling motorists from the south to Shah Alam and Klang while bypassing Kuala Lumpur. This section has been upgraded to eight-lane carriageway to accommodate heavy traffic due to this fact. Nilai