Butterworth–Kulim Expressway, BKE, (Malay: Lebuhraya Butterworth–Kulim), is the only opened toll system's expressway in Penang, Malaysia. The expressway connects Butterworth, Penang in the west to Lunas, Kedah in the east. It is also a main route to East–West Highway (Federal Route 4) via Baling, Kedah and Gerik, Perak. Route background The Butterworth–Kulim Expressway E15 is an east–west oriented expressway and concurrents with the Federal Route 4 and Asian Highway Route AH140 along its entire length. The actual starting point of the expressway is counted as Kilometre 5. Many maps have mistakenly labelled the section between Exit 1501 Kubang Sebang Interchange and Butterworth as a part of the E15 expressway; however, it is incorrect as the remaining 5-km section is not maintained by PLUS Malaysia Berhad but rather by Lingkaran Luar Butterworth (Penang) Sdn. Bhd. The zeroth kilometre is located at Jalan Heng Choon Thian at Butterworth Outer Ring Road's Container Terminal Interchange. History The construction of BKE started in December 1994 and was completed in September 1996. KLBK Sdn Bhd Konsortium Lebuhraya Butterworth-Kulim (KLBK) Sdn Bhd, commercially known as Buterworth Kulim Expressway (BKE), a wholly owned subsidiary of PLUS Expressway Berhad ("PLUS Expressways",) has been awarded the concession and contract to construct and operate the highway of dual two-lane carriageway with separate motorcycle tracks and related highway facilities for the 16.78 km highway. The concession period is for 32 years (June 1994 to June 2026, including two years construction period), after which the highway will be transferred to the Government. On 2011, the company was taken over to PLUS Malaysia Berhad and its subsidiary Projek Lebuhraya Usahasama Berhad. Features Geographically, the terrain between KM 5.00 (start point) and KM 11.00 is rather flat, passing through paddy field areas. From KM 11.00 to KM 19.00, the terrain is slightly undulating, where cut and fill slopes are common features. The terrain is again flat from KM 19.00 to KM 21.78 (end point), mainly passing through the estates and developing residential areas. Geometrically, there are four grades separated interchanges and one at grade interchange along BKE. Moreover, there are nine reinforced concrete bridges (three of those are river bridges, i.e., Sungai Mengkuang, Sungai Kulim and Sungai Karangan, whereas the rest are bridges over local roads or railway track). Tuanku Bainun Teachers Training Institute (Institut Perguruan Tuanku Bainun) (IPTB) High speed limit 90 km/h Four-lane dual carriageway SOS emergency phones Dedicated motorcycle lane Tolls