tailieunhanh - Thiết kế hệ thống đường xá

Tham khảo tài liệu 'thiết kế hệ thống đường xá', kỹ thuật - công nghệ, kiến trúc - xây dựng phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ROAD DIMENSIONS SPACE REQUIREMENT AT FULL SPEED 50 km h I ị Bus bus Lorry lorry Van van Van car Q-5 Ị t 025 0 50 1 00 I I Lorry bicycle SPACE REQUIREMENT AT LOWER SPEED 40km h jT Car car 0 t 2 50 0 50 2 50 0 25 025 ị I 4 4 00 13 Lorry bicycle Van bicycle Car car ------ clearance limit . limit of space for traffic Basic dimensions for traffic space and a selection of cases showing the clearance necessary for traffic passing in opposite directions both at full and lower speeds Car bicycle safe side clearance safe head room pedestrians clearance limit limit of space for traffic cyclist motor vehicle The road space necessary for the free movement of vehicles comprises vehicle size - pp. 432-3 side and head clearances an extra allowance for oncoming traffic and space for verges drainage gutters and hard shoulders. Based on a vehicle height of m the safe clearance height is m although it is better to allow m to cater for repairs to the carriageway surface. The safe side clearance - @ is dependent on the maximum speed limit for that area m for roads with 70 km h limit m with a limit of 50 km h. The basic space required for cyclists is 1 m wide by m high for pedestrians it is m by m. For sufficient head clearance for foot- and cycle paths should be allowed. The safe side clearance for cyclists is . 212 ROAD DESIGN To harmonise the design construction and operational use of roads standard cross-sections should be strictly observed unless there are special reasons. The standard cross-sections for open roads are shown here -Ạ T as are those for roads in built-up areas 2 . Notation . c6ms a-f the cross-sectional group with the basic lane width being 6 the number of lanes in both directions of travel m a central reservation physical separation of the directions of travel s a hard shoulder r path for cycle riders within the cross-section p parking bays or parking spaces on .