英语翻译(1) Lever terrainAny combination of grades and horizontal and vertical alignment that allows heavy vehicles to maintain approximately the same speed as passenger cars ; this terrain generally includes short grades of no more than 1 to 2 p

英语翻译(1) Lever terrainAny combination of grades and horizontal and vertical alignment that allows heavy vehicles to maintain approximately the same speed as passenger cars ; this terrain generally includes short grades of no more than 1 to 2 p
英语翻译
(1) Lever terrain
Any combination of grades and horizontal and vertical alignment that allows heavy vehicles to maintain approximately the same speed as passenger cars ; this terrain generally includes short grades of no more than 1 to 2 percent .
(2) Rolling terrain
Any combination of grades and horizontal and vertical alignment that causes drivers of heavy vehicles to reduce speeds to substantially bellow those of passenger cars ,but does not require operation at crawl speeds for any significant length of time .
(3) Mountainous terrain
Any combination of grades and horizontal aligrment that causes drivers of heavy vehicles to operate at crawl speeds for significant distances or at frequent intervals .
Crawl speed is the maximum sustained speed that heavy vehicles can maintain on an extended upgrade of a given percent .
These definitions are general and spend on the particular mix of heavy vehicles in the traffic stream .In general ,as terrain becomes more severe ,capacity and service flow rates are reduced .This impact is significant for two – lane rural highways ,where the severity of terrain not only affects the operating capabilities of individual vehicles in the traffic stream ,but also restricts the opportunities to pass slow – moving vehicles in the traffic stream .
In addition to the general impacts of terrain,isolated upgrades of significant length may have a substantial effect on operations .heavy vehicles slow significantly on such upgrades ,creating operational difficulties in the traffic stream and in efficient use of the roadway.
Grades also may have a major impact on operation of intersection approaches ; vehicles must overcome both the grade and the inertia of starting from a stopped position at the same time .

英语翻译(1) Lever terrainAny combination of grades and horizontal and vertical alignment that allows heavy vehicles to maintain approximately the same speed as passenger cars ; this terrain generally includes short grades of no more than 1 to 2 p
1)地形杠杆 任何等级、横向和纵向相结合的路线,使重型车保持同样的速度大约为轿车; 这包括一般地形短年级不超过1至2%.(2)地形滚动 任何等级的组合,横向和纵向协调,造成驾驶重型车辆的速度大大降低理那些轿车,而且不需要在爬行速度运行任何重大时间.(3)山地 任何组合档次和水平aligrment造成重型车司机在操作速度大大距离自由泳和重播.最高爬行速度持续速度,重型车将保持在一定的提升%.这些都是一般定义的特殊结构,用于重型车辆的车流.一般,地形变得更加严重,服务能力和流通率降低.这种影响是很大的双车道乡村公路,地形严重,不仅影响个人的业务能力车辆车流,也限制了机会通过慢速车在车流中.除了一般地形影响,个别重大升级时间可能有重大影响的行动.大大提高缓慢等重型车辆,造成运作上的困难,在车流有效利用道路.档次也有可能产生重大影响的交叉作业方式; 既要克服车辆的档次和惯性从一个位置同时停止.