Public bus services are provided by two firms - Rapid Penang and Cityliner. Due to Butterworth's importance as a transportation hub, most of the Rapid Penang's routes originate and terminate within the town. Rapid Penang's bus routes 601, 602, 603, 604, 605, 608, 701, 702, 703, 709 and 801 connect Butterworth with other towns within Seberang Perai, including Perai, Bukit Mertajam, Kepala Batas and Nibong Tebal, whilst the company's Intercity routes link Butterworth with Sungai Petani in Kedah and Parit Buntar in Perak. Cityliner operates another six bus routes which link Butterworth with a handful of destinations in Seberang Perai, Kedah and Perak.