2007, provincial expressways started using the same exit notification signs that national freeways started using in 2006. The following is a list of all provincial highways as of 2 August 2006: Ordinary Provincial Highways 1 (Taipei - Fenggang, Pingtung): This is the historical north–south highway (縱貫公路). 1A (Taipei - Taoyuan District, Taoyuan City) 1B (Daya, Taichung - Wangtian, Taichung) 1C (Changhua City bypass) 1D (Citong - Douliu) 1E (Kaohsiung - Houzhuang) 1F (Zhunan - Luzhunan) 2 (Guandu, Taipei - Su-ao, Yilan) (North Coast Highway) 2A (Jinshan, New Taipei - Taipei) 2B (Taipei - Tamsui, New Taipei) 2C (Nuannuan, Keelung - Daxi, Yilan) 2D (Badu, Keelung - Rueibin, New Taipei) 2E (Wujie - Su'ao) 2F (Dawuluan, Keelung - Keelung Harbor): An extension of Freeway 3. 2G (Toucheng, Yilan) 3 (Taipei - Pingtung City) 3A (Caotun, Nantou - Nantou City) 3B (Daxi, Taoyuan City - Shimen Dam 3C (Zhushan, Nantou - Jiji, Nantou) 4 (Dayuan, Taoyuan City - Shimen Reservoir) 5 (Taipei - Keelung City) 5A (Zhangshuwan, New Taipei - Liudu, Keelung) 5B (Xizhi bypass): Decommissioned in 2013. 6 (Houlong, Miaoli - Dahu, Miaoli) 7 (Daxi District, Taoyuan City - Zhuangwei, Yilan): (Northern Cross-Island Highway, 北部橫貫公路) 7A (Qilan - Lishan) 7B (Sanxia, New Taipei - Fuxing District, Taoyuan) 7C (Datong, Yilan - Wujie, Yilan) 7D (Yuanshan, Yilan - Yilan) 8 (Dongshi, Taichung - Taroko, Hualien) (Central Cross-Island Highway, 中部橫貫公路): This highway was severely damaged between Guguan and Deji by the 1999 Jiji earthquake although the Guguan-Lishan section opened to limited traffic in 2018. 8A (Baxin - Deji): This highway was severely damaged in the 1999 Jiji earthquake and has been shut down since. 9 (Taipei - Fenggang, Pingtung): The highway runs through the eastern part of Taiwan. It is the longest highway in Taiwan. 9A (Xindian, New Taipei - Wulai, New Taipei) 9B (Beinan-Taitung City bypass) 9C (Hualien - Shoufeng) 9D (Su'ao - Xiulin) 9E (Daren - Shizi) Suhua Improve(Limited-access) South Link Highway Improve(Limited-access) 10 (Taichung Harbor - Fengyuan District) 10B (Qingshui - Shalu) 11 (Hualien City - Taitung City): (Hualien-Taitung Coastal Highway) 11A (Guangfu - Fengbin) 11B (Taitung City) 11C (Ji'an - Shoufeng) 12 (Taichung Harbor - Taichung) 13 (Xiangshan, Hsinchu - Fengyuan District) 13A (Zhunan - Miaoli City) 14 (Changhua City - Lushan, Nantou) 14A (Wushe, Nantou - Dayuling, Hualien) 14B (Fenyuan, Changhua - Nantou City) 14C (Changhua City alternate) 14D (Fenyuan, Changhua - Nantou City) 15 (Guandu, Taipei -