It interchanges once in Gurun, bends southwest, then interchanges twice again near Sungai Petani, once to the northeast of the town and once to the southeast. The expressway crosses the bridge over the Muda River, which marks the border between the states of Kedah and Penang. The expressway reaches the town of Bertam, where route 1 deviates westwards from parallelism with the expressway. Further southwest is the Sungai Dua Toll Plaza, where the ticket system ends and the toll-free section begins. The expressway interchanges south of the plaza, just to the west of Sungai Dua. This interchange marks one terminus of the Butterworth Outer Ring Road (expressway 17), which goes west towards Bagan Ajam. After this interchange the expressway widens to six lanes and the urban speed limit of 90 km/h applies. The expressway then crosses the Perai River. Butterworth and Bandar Baharu From this point the expressway enters Seberang Perai Tengah, running southwesterly along the east side of Butterworth, where it makes several important interchanges, including Jalan Permatang Pauh (route 3111) leading to Permatang Pauh, the Butterworth–Kulim Expressway (expressway 15) towards Kulim and Gerik in Kedah, expressway 17 and route 1 in Perai (this is where the other end of E17 is located) as well as the Penang Bridge (expressway 36) towards the island and capital. Here the expressway bends southeast away from the coast, going towards and interchanging at the Perai Industrial Area and Juru. After Juru, the road narrows back to four lanes, followed by the Juru Toll Plaza, where the second ticket system begins. The expressway then enters Seberang Perai Selatan. The expressway interchanges with route 149 at Bukit Tambun, connecting several industrial areas nearby. Close by at Batu Kawan, the Sultan Abdul Halim Muadzam Shah Bridge (expressway 28) terminates on this expressway, connecting Bandar Cassia as well as the southwest district on the island. The last interchange in Penang is with route 1 at Jawi. The expressway then briefly re-enters the state of Kedah to interchange at Bandar Baharu, serving itself, Parit Buntar just across the border at Perak, as well as the rest of southernmost Kedah. Alor Pongsu to Ipoh Across the Kerian River is the Kerian district in Perak, where a new interchange with route 147 at Alor Pongsu is being constructed. The expressway then briefly winds eastwards, then southwards, to meet Bukit Merah. The expressway continues directly southwards into Larut, Matang dan