路桥工程专业英语赵永平第五课翻译

1、南昌大学第五课Traffic Engineering Introduction交通工程学概论A.Text: Traffic Engineering BasicsB.Reading Material: Highway CapacityTextTraffic Engineering Basics1 Prediction of Traffic V olume Growth交通量增长预测Traffic volume growth may be predicted using a number of methods but the two primary ones are the use of the

2、ARTS long-range plan and manual methods. The ARTS plan may be used to establish average daily traffic volumes for streets within a study area for a future year as predicted by the ARTS model. This data can be used to develop a factor to apply to existing traffic counts to predict future-year traffic

3、 volumes.使用了一些方法,可以预测交通量的增长,但两个主要的是远距离的艺术计划和手动的方法使用。艺术计划可能被用来建立一个研究区域内的街道由艺术模型预测未来一年的平均日均车流量。这些数据可以被用来开发适用于现有的交通计数的一个因素来预测未来年的交通量。Manual extrapolation of existing data using growth factors may be available from the City, or the consultant may need to develop them. Growth factors may be and can be re

4、presentative of a number of algebraic trends. Among these are the straight-line, exponential, and decaying-rate exponential trends. For a good discussion of these trend methods, see the Trip Forecasting Manual published by the Florida Department of Transportation. Generally, manual extrapolation of

5、turning movement counts will not be accepted for periods of time exceeding five years.手动现有数据推算,使用生长因子可能是从化市或顾问可能需要开发它们。生长因子可能是可以代表一些代数趋势。其中有直线,指数,腐烂率指数趋势。对于这些趋势的方法商量好了,看到的旅程预测佛罗里达运输部公布的手册。一般来说,手动外推转动计数将不被接受的时间周期超过五年。2 Trip Generation Estimation2出行生成估计Trip generation may be estimated using the Instit

6、ute of Transportation Engineers (ITE Trip Generation. An accompanying publication, the Trip Generation Handbook provides additional information on how to use Trip Generation and how to apply adjustments such as pass-by trips.使用交通工程师协会(ITE出行生成,出行产生可估计。一位随行的出版物,出行生成手册提供了额外的信息,如何使用出行生成和传递行程调整,如如何申请。Gen

7、erally, the City of Aiken accepts the methodology provided in Trip Generation and the Trip Generation Handbook. In some cases, trip generation data may not be available from ITE for certain land uses. In these cases the applicants consultant will be required to develop estimated trip generation data

8、 for use in the study after consultation with the City of Aiken staff.一般来说,市艾肯接受出行生成,出行生成手册中提供的方法。在某些情况下,出行生成的数据可能不会对某些土地用途从ITE。在这些情况下,将要求申请人的顾问估计出行生成的数据在研究中使用与市艾肯人员协商后制定。The Trip Generation provides estimated trip generation data for various land use categories, known as land use codes in the Manua

9、l. Average rates for weekdays, weekends, and morning and afternoon peak hours are given for most land use codes. In addition, many of the land use codes provide equations that may be used to determine estimated traffic generation. An example of the data for a land use, Code 210, single-family reside

10、ntial, is given on the following page. As seen in this example, there are average rates as well as an equation given for this particular land use. The Trip Generation Handbook gives information that recommends when to use the average rate data and when to use the equations. A summary decision chart

11、from the Handbook takes into account the size of the development and the statistics indicating the reliability of the data in Trip Generation. For example, for a single-family residential development, the average daily trip generation rate given is 9.57 trips per dwelling unit. The equation given is

12、 Ln(T = 0.92×Ln(X + 2.71. If a proposed single-family residential project has 300 dwelling units, then the equation would give the following estimate of daily trips:Ln(T = 0.92×Ln(300 + 2.71Solving for T gives 2857 trips. Using the average rate of 9.57 trips per dwelling unit would give 30

13、0×9.57 = 2671. So, there is a discrepancy between the two methods and a decision must be made as to which method to use.For a second example consider a proposed mini-warehouse facility with 125 units, land use code 151. In this case there is an equation given, but the formula is based upon only

14、 14 studies. As per Figure 4, we see that the number of data points is less than 20, so we check the standard deviation and see that it is 1.78 versus the average of 2.50 for a percentage of 72%. Since the R2 value is 0.73, which is less than 0.75, we would use the average of 2.50 per unit. This wou

15、ld result in 2.50×125 = 313 trips. The equation would have given:Ln(T = 1.01×Ln(125 + 0.82Solving for T gives 298 trips. Again, this is a different result than we would get with the average rate, but in this case the ITE Trip Generation Handbook recommends use of the average rate.As seen a

16、bove, care must be used when developing trip generation estimates from the ITE Trip Generation and the guidelines of the ITE Trip Generation Handbook must be used to make the correct selection between the use of average rates and equations provided.估计出行生成提供各种土地使用类别的出行生成的数据手册中,被称为土地使用代码。平日,周末,上午及下午繁忙

17、时间的平均利率,给出了大部分的土地使用代码。此外,许多的土地使用代码提供可用于确定估计流量生成的方程。土地使用的数据的一个例子,代码210,单一家庭住宅,下页。在这个例子中可以看出,有平均率,以及作为一个方程给出了这个特定的土地使用。出行生成手册提供的信息时,建议使用的平均汇率数据时,使用方程。考虑到规模发展和出行生成的数据的可靠性统计手册概要决策图表。例如,对于一个单一家庭住宅的发展,平均每天的出行生成率是每居住单位9.57人次。该公式为ln(T= 0.92×LN(X+ 2.71。如果一项拟议的单一家庭住宅项目有300个住宅单位,则方程给日常出行下面的估计:LN(T= 0.92&#

18、215;LN(300+ 2.71解为T给出了2857人次。每个住宅单位的平均增长率为9.57人次将给予300×9.57 = 2671。因此,有两种方法,必须决定使用哪种方法来之间的差异。在第二个例子中,有125个单位,土地使用代码151考虑拟议的迷你仓设施。在这种情况下,有一个公式,但公式是基于只有14项研究。按照图4中,我们看到的数据点的数量小于20,因此,我们检查的标准偏差,并看到,这是相对于平均为72%的百分比2.50 1.78。由于R2的值是0.73,小于0.75,我们会使用2.50每单位的平均值。这将导致在2.50×125 = 313人次。该公式将给予: LN(T

19、= 1.01×LN(125+ 0.82解为T提供了298人次。再次,这是一个不同的结果,比我们所得到的平均速率,但在这种情况下,ITE旅程代数手册推荐使用的平均速率。从以上可以看出,从ITE出行生成和ITE出行生成手册“的指导方针,必须使用之间的平均房价和提供的公式进行正确的选择时,必须使用制定出行生成预测。3 Traffic Assignment3交通分配Previously the estimation of generated trip ends has been discussed together with the distribution of trips between

20、 the traffic zones. Modal split methods also have been reviewed in which the proportion of trips by the varying travel modes are determined. At this stage the number of trips and their origins and destinations are known but the actual route through the transportation system is unknown. This process

21、of determining the links of the transportation system on which trips will be loaded is known as traffic assignment.此前估计生成的行程结束已经讨论了一起往返的交通区的分布。模态分割方法也已审阅出游的比例确定不同的出行方式。在这个阶段,游和它们的起源和目的地的数量是已知的,但通过运输系统的实际路由是未知的。确定的交通运输系统各环节的旅行将被载入这个过程被称为交通分配。Apart from the largest transportation survey traffic assign

22、ment tends to deal with highway traffic. This is because it is usually not difficult to estimate the route taken by public transport users and also because the loading trips on the public transport network dose not materially affect the journey time. Trip ends where there is no choise of travel mode

23、, which is from non-car-owing households, are accumulated as public transport trip ends. Choice trips where a car is available are separated by the modal choice procedure into car trips and public transport trips.除了最大的交通调查,交通分配趋于处理高速公路交通。这是因为它通常不是很难估计所采取的路线的公共交通用户,也因为装载旅行公共交通网络剂量并无重大影响的行车时间。旅程结束那里是没

24、有的choise出行方式,这是由于无车户,累计公共交通行程结束。选择旅行汽车是分开成小汽车出行和公共交通出行模式的选择过程。Usually it will then be found that proposed road network is overloaded and some car trips will need to be restrained. If a car cannot be used then some trips will not be made at all, while other trips will be transferred to public transpo

25、rt and accumulated.通常情况下,它会被发现拟建的道路网络负荷过重,一些汽车行程将需要克制。如果一辆车不能使用部分车次将不进行,而其他车次将转移到公共交通和积累。As the basis of assignment is usually travel time, the travel times on the network links will vary the imposed loading. In addition as travel time is used in the trip distribution process, it is necessary to car

26、ry out an iterative procedure between distribution, modal choice and assignment.由于转让的基础通常是出行时间,出行时间会有所不同,在网络上链接强加的负荷。此外旅游时间在出行分布过程中,有必要开展一个迭代过程之间分配模式的选择和分配。The change in speed with volume on a highway link is carried out using speed flow relationships for the varying highway types and it is interest

27、ing to consider just what are the effects of a speed change. Firstly it affects the choice of route because assignment is made on the basis of travel time through the network. Secondly it affects the destinations of trips because trips are distributed to varying destinations on the basis of travel t

28、ime when a gravity model is used. Finally it may affect the choice of travel mode because modal choice is often made a comparison of travel times.公路上的链接速度的变化量进行使用不同类型的公路速度流量关系,有趣的是,要考虑究竟是什么速度变化的影响。首先,它会影响,因为分配的旅行时间的基础上,通过网络的路由选择。其次,它会影响分发到不同的目的地之间的行程时间时,使用引力模型的基础上,因为旅行的目的地的旅行。最后,它可能会影响出行方式的选择,因为模式的选

29、择往往是做了一个对比的旅行时间。There are many problems associated with speed flow relationships , considerable variation being observed between differing highways even of the same type. There is also the additional problem that most transportation studies are based on 24-hour flows so that it is necessary to know

30、the hourly variation and the directional distribution of flows.有许多相关的问题与高速流动的关系,观察到相当大的变化,即使相同类型的不同的道路之间。也有另外的问题,大多数运输研究是基于24小时的流量,以便它是要知道每小时的变化和流动的方向分布。In assignment it is first necessary to describe the transport network to which trips are being assigned. The network is described as a series of no

31、des and connecting links; in a highway network the nodes would be the junctions and the links the connecting highways. Centroids traffic zones, at which it is assumed that all zonal trips are generated and to which they are attracted, are either at nodes or connected to them by additional links. The

32、 cost of using a link and a junction, usually in the form of travel times and delays, is given on the basis of the review of transport facilities carried out during the initial stages of the transportation survey.分配首先要说明的交通网络,被分配车次。该网络被描述为一系列的节点和连接连杆的公路交通网的节点。将路口了该书的连接公路。质心的交通区,它假定所有纬向人次生成和它们所吸引,无论是

33、在节点或连接到它们额外的链接。使用链路和结点中,通常会在旅行时间和延迟的形式,给定的成本的基础上,运输调查的初始阶段进行的交通设施的评论。There are three methods by which the assignment may be made. These are:(1All-or-nothing assignment(2Capacity restrained assignment(3Multipath proportional assignmentIn all-or-nothing assignment method, an algorithm is used to compu

34、te the route of least cost, usually based on travel time between all the zone centroids. For each zone centroids selected as origin, a set of shortest routes from the origin to all the other centroids is referred to as a minimum tree. When the trips between two zones are assigned to the minimum path

35、 between the two zones, then the assignment is said to take place on all-or-nothing basis.该转让可能作出有三种方法。它们是:(1全有或全无的分配(2能力内敛的分配(3多径的比例分配全有或全无的分配方法,算法是用来计算最低成本的路线,通常是根据对所有区域的重心之间的旅行时间。对于每个区域选定的质心为原点,从原点到所有其他的质心的最短路线的一组被称为作为一个最小的树。当两个区域之间的车次,然后被分配到两个区域之间的最小路径的分配被认为是全有或全无的基础上。There are obvious difficult

36、ies with such a simplified approach, some of which are inherent in the other assignment methods. It is obviously incorrect to assume that all trips commence and terminate at a zone centroid. K the length of the links within the zones is small compared with the length of remainder of the minimum link

37、 path, then the errors may not be so serious. Because of its simplicity, travel time is usually employed as a measure of link impedance, but travel times may not be precisely estimated by the traveler. The use of a cost function which reflects the perceived cost of travel is desirable. The loading o

38、n a link in this method is extremelysensitive to estimated link and node costs, if these have been incorrectly estimated, then the resulting assignment is open to question. There is also the problem that links with small travel cost will attract trips without any adjustment in link cost.存在着明显的困难,这样一

39、种简化的方法,其中有一些固有的其他分配方法。这显然是不正确的假设,所有行程开始和终止区域重心。K的长度的区域内的链接的最低链路路径的其余部分的长度相比是很小的,则错误可能不那么严重。由于其简单性,旅行时间通常作为衡量链路的阻抗,但由旅行者的旅行时间可能不会很精确地估计。反映了知觉的旅行费用的成本函数的使用是可取的。加载一个链接这种方法是extremelysensitive的的链路和节点成本估计,如果这些不正确的估计,那么所得到的分配是值得商榷的。也有与小旅行费用的问题,没有任何调整链路成本将吸引前往。4 Traffic Flow Analysis4交通流分析Prior to developme

40、nt of traffic flow analysis for both existing and future conditions, a review will be made by the consultant and a proposed plan will be submitted to and discussed with the Planning Director. This plan will address the methods to be used in data collection and analysis.发展现有和未来的条件下交通流分析之前，将检讨顾问将提交建议计

41、划，并 讨论与规划总监。该计划将被用于数据收集和分析的解决方法。 Generally , traffic flow analysis will be by the current version of the Highway Capacity Manual (HCM. Computerized software packages such as HCS+, Synchro, SimTraffic, Corsim, and other programs may be used with prior approval of the Planning Director. 一般情况下，交通流分析将公路

42、容量手册（HCM）的当前版本。 HCS +， 同步，SimTraffic，CORSIM，和其他程序，如电脑软件套件可用于与事先批准 规划主任。 Any deviations from typical values for parameters used in the HCM or any software packages will require prior approval of the Planning Director. Among these parameters are standard normal ranges of saturation flow for travel lan

43、es, general traffic signal timing settings, normal values for percentages of heavy vehicles, and various adjustment factors. The consultant should discuss the use of any extraordinary settings for these and any other parameters with the Planning Director before use. For example, the Highway Capacity

44、 Manual normally recommends the use of a saturation flow of 1900 vehicles per hour for arterial streets. Use of a saturation flow rate substantially different would require prior approval of the Planning Director. 任何偏离从典型 HCM 或任何软件包中使用的参数值将需要事先批准的规划主 任。在这些参数中的旅游专线，交通信号定时设置，重型车辆的正常参考值的百 分比， 以及各种调整因素的

45、饱和流量的标准正常范围内。顾问应讨论使用任何特 殊设置，这些和任何其他参数使用前策划总监。例如，“公路容量手册通常建议 使用干道饱和流量每小时1900辆。实质上不同的饱和流量的使用，需要事先批 准的规划主任。 Words and Expressions Prediction：预测； Primary：原始的、初等的、基本的； manual ：手册、指南； Factor：系数； growth factors：增长系数； Consultant：求教者、征求意见者； Representative：表现的、代表性的，代表； Trend：走向、趋势； Exponential：指数； Discussion：议论、讨论； Count：算、计数； Institute：协会、学会； Handbook：手册； pass-by trips：过境出行； land use：土地利用； Require：要求、命令、需要； Staff：杖、杆，支柱，标尺，职员、参谋； a number of：若干、许多； long-range：远程的，长期的； ARTS plan： ARTS 图(计划； Extrapolation：推断、外推； Available：