UrbantransportationPlanning毕业设计外文翻译

1、本科毕业设计（论文）外文翻译专业名称：土木工程年级班级：学生姓名：指导教师：河南理工大学土木工程学院二 年 月 日urban transportation planning an urban transportation system is basic component of an urban area's social，economic，and physical structure. not only does the design and performance of a transportation system provide opportunities for mobili

2、ty，but over the long term，it influences patterns of growth and the level of economic activity through the accessibility it provides to land. planning for the development or maintenance of the urban transportation system is thus an important activity，both for promoting the efficient movement of peopl

3、e and goods in an urban area and for maintaining the strong supportive role that transportation can play in attaining other community objectives.there are several basic concepts about an urban transportation system that should be kept in mind. most important，a transportation system in an urban area

4、is defined as consisting of the facilities and services that allow travel throughout the region，providing opportunities for:(i)mobility to residents of an urban area and movement of goods and (2) accessibility to land .given this definition，an urban transportation system can be further characterized

5、 by three major components: the spatial configuration that permits travel from one location to another; the transportation technologies that provide the means of moving over these distances; and the institutional framework that provides for the planning, construction, operation, and maintenance of s

6、ystem facilities.the spatial configuration of a transportation systemone way to describe the spatial dimension of an urban transportation system is to consider the characteristics of individual trips from an origin to a destination. for example, a trip can consist of several types of movement undert

7、aken to achieve different objectives. travelers leaving home might use a local bus system to reach a suburban subway station(a trip collection process)，proceed through the station to the subway platform (a transfer process)，ride the subway to a downtown station (a line-haul process)，and walk to a pl

8、ace of employment (a distribution process). similarly，one can view a home-to-work trip by car as consisting of similar segments，with the local street system providing the trip collection process, a freeway providing the line-haul capability，a parking lot in the central business district serving as a

9、 transfer point，and walking，as before，serving the distribution function.the facilities and services that provide these opportunities for travel，when interconnected to permit movement from one location to another，form a network. thus，another way of representing the spatial dimension of an urban trans

10、portation system is as a set of road and transit networks. even in the smallest urban areas，where mass transit is not available，the local street network provides the basic spatial characteristic of the transportation system.the transportation system of a city can influence the way in which the city&

11、#39;s social and economic structure, often called the urban activity system，develops. at the same time，changes in this structure can affect the ability of the transportation system to provide mobility and accessibility. thus , the transportation system is closely related to the urban activity system

12、 and; historically, has been an important determinant of urban form.because of the relation between transportation and urban activities，many of the methods used by transportation planners depend on estimates of trips generated by specific land uses. the relation also suggests that the options availa

13、ble to public officials dealing with transportation problems should include not only those related directly to the transportation system, but also actions such as zoning that affect the distribution of land use, and thus influence the performance of the transportation system.the foregoing considerat

14、ions point to two important principles for transportation planning: the transportation system should be considered as an integral part of the social and economic system in an urban area.viewed as a set of interconnected facilities and services designed to provide opportunities for travel from one lo

15、cation to another.the technology of urban transportation the technology of urban transportation is closely related to the spatial configuration of the transportation system in that the design transportation networks reflects the speed, operating , and cost characteristics of the vehicle or mode of t

16、ransportation being used. technology includes the means of propulsion, type of support，means of guidance，and control technique.the development and widespread use of electric streetcars in urban areas during the late nineteenth century was a technological innovation that initiated the transformation

17、of most north american cities. the advent of the electric streetcar permitted urban areas to expand beyond the boundaries that had been dictated by previous transportation technologies (e. g.，walking，horse，horsecar)，spawning streetcar suburbs' with dramatically lower residential densities along

18、streetcar lines radiating from the central city. whereas many industries had decentralized along railroad lines leading from the central city，and workers initially had to live near these factories, the introduction of streetcars now permitted more distant living.the success of the streetcar in provi

19、ding access from selected suburban areas to central business districts was followed by public acceptance of a second major technological innovation-the automobile，powered by the internal combustion engine. increasing consumer preferences for lower-density living and for an ability to travel beyond e

20、stablished urban boundaries sparked a phenomenal growth in automobile ownership and usage，beginning in the 1920s . the automobile continues and accelerated the evolution of urban structure started by the electric streetcar. its availability permitted further expansion of urban areas and, more import

21、ant, provided access to land between the radial streetcar and railroad lines leading into the central city.the technology of the internal-combustion engine，however, also led to the decline of other transportation modes used in urban areas by providing a less expensive and more flexible replacement f

22、or rail-based modes. while the automobile provided new opportunities for personal mobility and urban growth, motor buses rapidly replaced electric streetcars, to the extent that only five north american cities today still operate large-scale streetcar systems-boston, philadelphia, pittsburgh, toront

23、o, and san francisco (although this trend has reversed somewhat in recent years with new light rail' systems in operation in edmonton, calgary, san diego, and buffalo). at the same time, the growth of private automobile use has dramatically reduced the use of public transportation in general, pa

24、rticularly since the end of world war ii. according to the latest census figures, in 1980, 62. 3 million americans normally drove alone to work each day, another 19 million car-pooled, and 6 million used public transportation.the technologies and the resulting modes available today for urban transpo

25、rtation are common to most cities but are often applied in different ways to serve different purposes. it should be noted that certain types of modes are appropriate than others in serving different types of urban trips.the technological dimension of the urban transportation system suggests a third

26、principle for urban transportation planning:transportation planners must consider the transportation system as consisting of different modes , each having different operational and cost characteristics.from; michael d. meyer and eric j. miller "urban transportation planning", 1984城市交通规划城市交

27、通系统是市区的社会、经济、和物质结构的一个基本组成部分。一个交通系统的设计和实施不仅为流动性提供机会，并且从长远观点来看，通过它能对土地提供良好使用价值也使经济活动和发展受到益处。这样，为了发展和维护城市交通系统而制定的规划是一项重要的活动，既是为了促进人和货物在市区的有效运转，同时也是为了保持交通在实现其他社团目标方而所能起到的强有力的支援作用。对于城市交通系统有几个基本概念是应该记住的。最重要的是,一个城市的交通系统被认为是包括交通设施和服务,这两者有助于贯穿全区的出行，并且为以下两方面提供机会:(1)居民的流通量和商品的运转，(2)对于土地的可达性。鉴于这种认识,城市交通系统可以进一步分

28、解为以下三个部分:空间布置,可使一点到另一点的出行成为可能；交通技术,提供两地区运转的手段；机构的机制，提供交通系统设施的规划、建设、运营和维护。交通系统的空间布置 描述一个城市交通系统的空间尺度的方式是考虑一个人由起点到目的地的出行特点。例如，出行可以包括为达到不同目的的几种类型的流动。离开家的出行者可以乘坐当地的公共汽车而到达另一个郊区地铁车站（出行集合过程），经车站转到地铁站台（换乘过程），乘地铁到达一个商业车站（沿线运行过程），然后步行到工作地点（分散过程）。相似的，人们可以把乘汽车由家到工作地点的出行看作是包括相似的过程，利用当地的街道系统实现出行集合过程，高速公路提供线路的出行能力

29、，在商业中心区的停车场起到换乘点的作用，而步行与前面说的一样，起到分散作用。当提供这些出行机会的公共设施和服务集合起来,使从一个地点到另一个地点的运动成为可能时就会形成网络。这样，表示一个城市交通系统的空间尺度的另一种方式是一组道路和公共交通的网络系统。甚至在不能利用公共交通的很小的市区内，当地的街道网络也会提供交通系统的基本空间特征。城市交通系统将会影响到城市的社会和经济结构（通常被称为城市活动系统）的发展方式。同时,这种结构的变化会影响交通系统提供流动性和可达性的能力。因此,交通系统是与城市活动系统密切相关的;从历史上看,城市交通系统曾经是一个决定城市形态的重要因素。由于交通和城市活动之间

30、的关系，许多交通规划人员所使用的方法取决于特定的土地利用所产生的出行评估。这个关系还暗示可供与交通问题打交道的政府官员多采用的选择方案。而且也应该包括，例如，影响土地利用分布的区域划分，并因此影响到交通系统特性的一些措施。上述的考虑指出用于交通规划的两个重要原则：被认为是市区社会和经济系统的一个完整部分。 被视为目的在于提供从一个地点到另一个地点出行机会的一套互相结合的交通设施和服务。城市交通的技术城市交通技术是同交通系统的空间布局紧密相关的，其中交通网设计反映车辆的速度、运行和费用特征所采用的交通模式。技术上包括推进的手段。支撑的类型引导的手段，以及控制技术。十九世纪晚期，在市区发展和广泛使

31、用有轨电车是一项技术创新，启动了北美大多数城市的转型。有轨电车的出现使城市地区超出了之前运输技术（例如走路、骑马、马车）所限定的界限进行了扩展。产生了大量的居住密度明显很低的位于由市中心辐射出去的电车电车路线沿线的“电车郊区”。与此同时，许多工业也从由市中心延伸出去的提路沿线疏散了，工人们起初需要在这些工厂附近居住，现在引进了电车，住的远也没有什么关系了。 在电车提供由经过挑选的郊区到中心商业区的道路取得成功后，接着是公众对于第二个重大技术革新，即对内燃机为动力的汽车的欢迎。消费者越来越多的对于低密度的居住生活的热爱，以及对于跨越已确定的城市边界出行能力的偏爱，促进了从二十年代开始的汽车购置和

32、使用方便急剧增长。汽车的可用性促使市区进一步扩展，并且更重要的是，汽车为通向市中心的放射状电车线和铁路路线之间地区的可能性提供条件。 然而，由于内燃机技术提供了比有轨交通方式更为廉价的和更为灵活的汽车，从而导致了市区内其他交通方式的衰落。在汽车为个人流通和和城市发展提供了新机会的同时，公共汽车很快取代了电车，以致目前只有五个北美城市还在使用大型电车系统，即波士顿、费城、匹茨堡、多伦多和旧金山（不过近年来这种趋势又有点逆转，新型“轻轨”系统正在埃德蒙顿、卡尔加里、圣地亚哥和布法罗运营）。于此同时，特别是自第二次世界大战结束以来，私人汽车使用的增长，一般来说已显著的使公共交通的使用缩减。根据最近的

33、统计数字，在1980年有六千二百三十万美国人每天是自己驾驶汽车上班，另外有一千九百万人合伙使用汽车，而有六百万人乘用公共交通。当前可以应用的城市交通技术和交通模式，对于大多数城市来说是通用的，但也常常以不同的方式应用，为不同的目的服务。应当注意到，某些交通方式较其他方式更适合于承担不同类型的城市出行。 城市交通系统的技术方面提出一个用于城市交通规划的第三个原则： 交通规划人员应当认为交通系统包括不同的交通方式，每一个方式具有不同的运营和费用特征。 摘自：迈克尔 d.梅耶和艾瑞克 j.米勒城市交通规划，1984traffic signalsin the united states alone ,

34、some 250,000 intersections have traffic signals , which are defined as all power-operated traffic-control devices except flashers，signs，and markings for directing or warning motorists, cyclists，or pedestrians. signals for vehicular，bicycle，and pedestrian control are pretimed where specific times int

35、ervals are allocated to the various traffic movements and as 'traffic actuated' where time intervals are controlled in whole or in part by traffic demand. pretimed traffic signals'pretimed' traffic signals are set to repeat regularly a given sequence of signal indications for stipula

36、ted time intervals through the 24-hr day. they have the advantages of having controllors of lower first cost and that they can be interconnected and coordinated to vehicles to move through a series of intersections with a minimum of stops and other delays. also, their operation is unaffected by cond

37、itions brought on by unusual vehicle behavior such as forced stops，which，with some traffic-actuated signal installations may bring a traffic jam. their disadvantage is that they cannot adjust to short-time variations in traffic flow and often hold vehicles from one direction when there is no traffic

38、 in the other. this results in inconvenience, and sometimes a decrease in capacity.cycle length the time required for a complete sequence of indications, ordinarily falls between 30 and 120s. short cycle lengths are to be preferred, as the delay to standing vehicles is reduced. with short cycles, ho

39、wever a relatively high percentage of the total time is consumed in clearing the intersection and starting each succeeding movement. as cycle length increases, the percentage of time lost from these causes decreases. with high volumes of traffic, it may be necessary to increase the cycle length to g

40、ain added capacity. each traffic lane of a normal signalized intersection can pass roughly one vehicle each 2.1s of green light. the yellow (caution) interval following each green period is usually between 3 and 6s，depending on street width，the needs of pedestrians, and vehicle approach speed. to de

41、termine an approximate cycle division, it is common practice to make short traffic counts during the peak period. simple computations give the number of vehicles to be accommodated during each signal indication and the minimum green time required to pass them. with modern control equipment, it is po

42、ssible to change the cycle length and division several times a day, or go to flashing indications to fit the traffic pattern better.at many intersections，signals must be timed to accommodate pedestrian movements. the manual recommends that the minimum total time allowed be an initial interval of 4 t

43、o 7s for pedestrians to start plus walking time computed at 4 ft/s (1. 2m/s). with separate pedestrian indicators，the walk indication(lunar white) covers the first of these intervals, and flashing don't walk (portland orange ) the remainder. the walk signal flashes when there are possible confli

44、cts with vehicles and is steady when there are none. steady don't walk tells the pedestrian not to proceed.if pedestrian control is solely by the vehicle signals，problems develop if the intersection is wide, since the yellow clearance interval will have to be considerably longer than the 3 to 5s

45、 needed by vehicles. this will reduce intersection capacity and may call for a longer cycle time. on wide streets having a median at least 6 ft (1. 8m)wide，pedestrians may be stopped there. a separate pedestrian signal activator must be placed on this median if pedestrian push buttons are incorporat

46、ed into the overall control system.coordinated movementfixed-time traffic signals along a street or within an area usually are coordinated to permit compact groups of vehicles called platoonsto move along together without stopping. under normal traffic volumes，properly coordinated signals at interva

47、ls variously estimated from 2500 ft (0. 76km)to more than a mile (1. 6km) are very effective in producing a smooth flow of traffic. on the other hand，when a street is loaded to capacity，coordination of signals is generally ineffective in producing smooth traffic flow.four systems of coordination-sim

48、ultaneous, alternate，limited progressive, and flexible progressive-have developed over time. the simultaneous system made all color indications on a given street alike at the same time .it produced high vehicle speeds between stops but low overall speed. because of this and other faults，it is seldom

49、 used today.the alternate system has all signals change their indication at the same time，but adjacent signals or adjacent groups of signals on a given street show opposite colors. the alternate system works fairly well on a single street that has approximately equal block spacing. it also has been

50、effective for controlling traffic in business districts several blocks on a said, but only when block lengths are approximately equal in both directions. with an areawide alternate system，green and red indications must be of approximately equal length. this cycle division is satisfactory where two m

51、ajor streets intersect but gives too much green time to minor streets crossing major arteries. other criticisms are that at heavy traffic volumes the later section of the platoon of vehicles is forced to make additional stops，and that adjustments to changing traffic conditions are difficult.the simp

52、le progressive system retains a common cycle length but provides 'go' indications separately at each intersection to match traffic progression. this permits continuous or nearly continuous flow of vehicle groups at a planned speed in at least one direction and discourages speeding between si

53、gnals. flashing lights may be substituted for normal signal indications when traffic becomes light. the flexible progressive system has a master controller mechanism that directs the controllers for the individual signals. this arrangement not only gives positive coordination between signals，but als

54、o makes predetermined changes in cycle length，cycle split，and offsets at intervals during the day. for example，the cycle length of the entire system can be lengthened at peak hours to increase capacity and shortened at other times to decrease delays.flashing indications can be substituted when norma

55、l signal control is not needed. also the offsets in the timing of successive signals can be adjusted to favor heavy traffic movements, such as inbound in the morning and outbound in the evening. again，changes in cycle division at particular intersections can be made. the traffic responsive system is

56、 an advanced flexible progressive system with the capacity to adjust signal settings to measured traffic volumes. where traffic on heavy-volume or high-speed arteries must be interrupted for relatively light cross traffic，semi-traffic-actuated signals are sometimes used. for them，detectors are place

57、d only on the minor street. the signal indication normally is green on the main road and red on the cross street. on actuation, the indications are reversed for an appropriate interval after which they return to the original colors.交通信号仅在美国，约250000十字路口有交通信号,这被定义为所有除了闪光灯、标志、和标记的用于指导或警告驾驶员、骑自行车的人和行人的电

58、动交通控制装置,。 控制车辆，骑自行车的人和行人的信号是在特定时间间隔分配到各种交通活动的预定时间和在交通运转中控制全部或部分交通需求的的时间间隔。定时交通信号 定时交通信号是设定为在一天二十四小时内规定的时间定期重复一个规定的信号指示。它们有这些优势，包括有低生产成本的控制器，可以联系和协调使车辆以最少的停靠和其他的延迟通过一系列的交叉口。而且，它们的操作不受异常车辆行为引起的状况的的影响，如一些交通信号控制装置可能带来的交通堵塞引起的强迫性停车。它们的劣势是它们无法适应交通流量的变化和在没有其他交通的情况下约束一个方向的车辆。结果是导致交通不便和有时的通行能力下降。 一套完整顺序的“周期时间”通常在30秒到120秒之间。当车辆延迟减少，短循环时间是优先考虑的。然而对于短循环，清理路口和开始每一次顺利的运转消耗的时间相对较高。当循环周期增加，从这些原因失去的时间减少。对于高流量的交通，可能需要增加循环周期来获得更大的通行能力。 每一个行车道信号正常的路口，一辆车在绿灯下大约2.1秒通过。根据街道宽度、行人需求和车辆靠近速度，每一个绿灯周期后的黄灯（警示）间隔在3秒到6秒之间。要确定一个大致的周期划分，常见的做法是确定高峰期间的短期交通数目。简单的计算给出每一个适