Design Standards of Urban Roads and Accessory Works Article 14

Regulations governing the urban road grade separation crossing structural designs:1. The lateral clearance between the outside wall of urban road grade separation crossing structures and outside wall of building structures shall be at least 4.5 meters for grade separation structures and at least 3 meters for ramp structures.2. Height clearance of the grade separation crossing over the underlying road shall be at least 4.6 meters. Grade separation crossing sections where large vehicles are prohibited from entering shall have height clearance of at least 0.5 meters added to the height of largest vehicles; moreover, height limiting or warning devices shall be installed.3. Where level side lanes are constructed, lane width shall be at least 3 meters; moreover, space for U-turn lane shall be allocated.