Design Standards of Urban Roads and Accessory Works Article 23
Regulations governing the tunnel designs of urban roads:1. The clear width of the tunnel cross section for tunnels equipped with single lanes shall be at least 5 meters; for tunnels equipped with double lanes, clear width shall be at least 7 meters. Clear width of the maintenance pathway shall be at least 0.7 meter.2. The perpendicular clearance of the tunnel lane shall be at least 4.6 meters; where entry of large vehicles is prohibited, height clearance shall beat least 0.5 meters added to the height of largest vehicles; moreover, height limiting or warning devices shall be installed at the tunnel entrances.3. Drainage, ventilation and lighting facilities, traffic monitor and safety facilities shall be constructed or installed pursuant to requirements.
中文原文 市區道路及附屬工程設計標準第23條
市區道路之隧道設計規定如下：
一、隧道橫斷面淨寬，設置單車道者不得小於五公尺；設置雙車道者，不得小於七公尺；維護步道寬度，不得小於零點七公尺。
二、隧道內車道垂直淨高，不得小於四點六公尺；限制車種通行者，淨高不得小於最大可通行車輛高度加零點五公尺，並應設置限高架及警告設施。
三、依需要配置排水、通風、照明、交通監控及安全附屬設施。
一、隧道橫斷面淨寬，設置單車道者不得小於五公尺；設置雙車道者，不得小於七公尺；維護步道寬度，不得小於零點七公尺。
二、隧道內車道垂直淨高，不得小於四點六公尺；限制車種通行者，淨高不得小於最大可通行車輛高度加零點五公尺，並應設置限高架及警告設施。
三、依需要配置排水、通風、照明、交通監控及安全附屬設施。