公路路线设计规范 JTG D20-2017(英文版)

1 General Provisions 1 2 Highway Classification and Class Selection 3 2. 1 Highway function and classification 3 2. 2 Selection of highway technical classification and design speed 5 2. 3 Control of access 7 3 Highway Capacity 10 3. 1 General 10 3. 2 Level of service 11 3. 3 Design hourly volume for highway 13 3. 4 Design capacity of motorway or Class-1 highway segments 14 3. 5 Capacity of interchange 16 3. 6 Capacity of a Class-2 or Class-3 highway 17 4 Overall Design 19 4. 1 General 19 4. 2 Highway function and technical criteria 19 4. 3 Scope of project and implementation plan 20 4. 4 Environmental stewardship and resource conservation 24 4. 5 Design checking and safety assessment 25 5 Highway Route Location 27 6 Highway Cross-sections 31 6. 1 General 31 6. 2 Traffic lane 33 6. 3 Median 36 6. 4 Shoulders 37 6. 5 Road crown and cross-slope 39