Unit
1The Evolution of Transport交通工具的演化
The evolution of transport has been closely linked to the development of humankind throughout the earth’s history．Transport’s early function was to meet the basic need of hauling food supplies and building materials．But with the formation of tribes，then peoples，and finally nations，the societal and economic functions of transport became more and more complex.At first there was mobility required for individuals，clans，households，and animals to protect them against，and to escape from，the dangers of natural disasters and tribal aggreions，and in the search for the best places to settle．As tribal groups formed and gradually established their geographical identity，transport was increasingly needed to open up regions for development，to provide acce to natural resources，to promote intercommunal trade，and to mobilize territorial defense．When the first nations came into being，transport played a major role in establishing national integrity．
交通工具的演变紧密相连的人类在整个地球的历史发展。运输署早期功能是满足基本需要搬运粮食供应和建材等领域。但随着部落，然后人民，和最后国家形成，运输的社会和经济功能变得越来越复杂。在第一次有流动性所需的个人、宗族、家庭和动物保护他们免遭，和逃避危险自然灾害和部落的侵略行为，并在寻找最好的地方定居。部落群体形成和逐步确立其地理特征，运输日益需要开放地区的发展，以提供对天然资源，促进族裔间的贸易，并调动本土防卫的访问。当第一次的联合国应运而生时，运输发挥了重要的作用，建立民族气节
After basic societal needs had generally been attended to，local communities could increasingly devote their efforts to enhancing their economic，cultural，and technological development through trade links with other peoples and regions．Again，transport provided the mobility required for such intertribal, international，and finally intercontinental cultural exchange and trade．During all of this gradual development toward an organized human society，represented today through the international family of nations，transport as physical proce of moving people and goods，thus promoting such development，continuously underwent technological and organizational changes．Such changes were induced by several factors and circumstances．In fact，today’s transport in its various forms and organizational arrangements remains highly subject to changes in response to societal requirements and preferences．
基本社会需求大体上已照顾到后，当地社区可能会越来越多地致力于加强贸易联系通过与其他民族和地区经济、文化和科技发展共同。再次，运输提供所需的这种部落之间、国际和洲际最后的文化交流和贸易的流动。在所有有组织的人类社会，今天代表国际大家庭，交通工具的移动人员和货物，物理过程，从而促进这种发展，通过向此逐步发展的过程中不断发生了技术和组织的变化。这种变化是几个因素及环境所致。事实上，今天的各种形式和组织安排运输仍高度受回应社会需求和偏好的变化。
Clearly，the first and foremost criterion to be satisfied by transport was efficiency．For centuries，and particularly during the takeoff stages of local economics，society required reliable，fast，and low cost transport．The search for appropriate technologies was relatively unconstrained．There were times in human history when the demand for reliable and fast transport was especially pronounced，and quick solutions were required for national self-defense.During such periods of local and international conflict, human ingenuity devised new transport technologies which often proved to be the decisive element for survival, and sometimes victory.Subsequently refined and developed, such new technologies made it poible to better meet increasing transport demand, thus improving both economic progre and human welfare.显然符合运输的首要准则是效率。几百年来，特别是在本地经济的起飞阶段期间，社会需要快速、可靠、和低成本的运输。寻找合适的技术是相对无约束。倍时，在人类历史上尤为突出的可靠、快速的运输需求，并快速解决方案所需的国家自卫。在这样的地方和国际冲突的时期人类智慧制定新运输技术往往证明的生存空间，有时胜利的决定性因素。随后改进和发展，这种新技术使能够更好地满足日益增加的交通需求，从而提高经济进步和人类福祉。
The need for better strategic mobility induced efforts to improve sea and land transport.This resulted in bigger and faster ships and more reliable and sturdy land vehicles.Eventually, self-propulsion was introduced, exemplified by steamboats, the railways, and then the automobile.Research and development in the transport field finally became an organized undertaking with specific goals and objectives.As the result of the consequent concentration of talent and expertise, more and more sophisticated transport technologies evolved, such as the aircraft and, most recently, rocket propulsion.需要更好的战略机动致努力提高海洋和陆地运输。这导致更大、更快的船舶和更可靠和坚固的陆地车辆。最终，自航引入，蒸汽机船、铁路和汽车的例子。在运输领域研发终于成为组织的承诺与特定的目标。作为随后浓度的人才及专业知识的结果，更多先进的传输技术如飞机和，最近，火箭推进发展。
The gradual evolution of increasingly sophisticated means of transport is manifested by today\' s transport systems, which include air, surface, and water transport.Special industry needs have led to the development of transport modes that have rather limited applications, such as pipelines, cables, and belts.Within current societal needs and preferences, as well as the economic requirements of cost effectivene, the various existing transport modes generally fulfill rather specific functions.今天的表现是逐渐演化的日益复杂的交通工具 \' s 运输系统，其中包括空中、地面、和海上运输。而是有限的应用程序如管道、电缆和带的交通工具的发展导致特殊行业的需要。当前社会的需要和喜好，以及成本效益的经济上的要求，在现有的各种运输模式普遍达到而是特定的功能。
Although transport\'s potential to meet effectively numerous societal mobility needs improved continuously, it became evident that such effectivene had its price.A number of transport technologies implied high energy consumption and required substantial capital inputs in production and operation.As a result, several transport modes became expensive to the user.This caused equity problems because charges required to cover operating costs were not affordable by all population groups, thus limiting their mobility and welfare.Many governments chose to subsidize transport, but quickly realized that the budget implications often caused serious distortions in their national economies.虽然运输的潜力以满足有效众多社会流动性需要不断改善，很明显这种有效性了它的价格。运输技术的一些暗示能耗高，所需大量资金投入生产和经营。因此，几个交通工具变得昂贵给用户。这造成了股权问题，因为业务费用所需的费用不是负担得起的所有人口群体，从而限制了他们的流动性和福利。许多国家的政府补贴交通工具，选择了，但很快意识到，所涉预算问题经常在自己国家的经济造成严重扭曲。
Pollution caused by various transport modes gradually became another serious problem as world transport in most countries and the need to cope with rising volumes of commodity flows and person travel.In several regions of the world having high population and industry concentrations, such detrimental impacts on the environment have reached high levels.These effects of such damage yet are to be fully explored.逐渐引起各种交通工具的污染成了另一个严重的问题，作为世界交通在大多数国家和应付日益增加的商品流动和人旅行的需要。过高的人口和产业的浓度在世界一些地区，这种对环境的不利影响已达到高水平。这种损害的这些影响还很充分探讨。
Finally, problems caused by dwindling world energy resources, particularly petroleum, have increasingly impeded transport services and operations.Most existing transport modes are critically dependent on petroleum derivatives for proper functioning.With unabated growth of demand for transport and a progreively limited supply of energy, the costs of providing transport have increased steadily.In particular, the disproportion of petroleum requirements and petroleum supply has caused serious inflationary problems to arise in many countries.Especially hard hit are countries with a partial or total dependence on an external petroleum supply, which have experienced growing deficits in their current accounts.最后，特别是石油、世界能源资源日益减少，所引起的问题越来越多地阻碍了交通服务和操作。大多数现有交通工具都依赖石油衍生品的正常运作。对交通的需求有增无减，逐步有限的能源供应提供运输的费用稳步增加。特别是石油需求和石油供应的非均衡性，引起严重的通胀问题在许多国家中出现。打击尤其是部分或全部依赖外部的石油供应，经历了它们的经常账户赤字不断增长的国家。
The transport sector\' s increasing inability to satisfy demand efficiently and equitably is a problem with which all nations have to cope in trying to advance economic and social progre.Energy-supply constraints, high capital and operating costs, often with exceive foreign-exchange components, and the seriousne of transport-related environmental pollution account in large part for this problem.But transport is and will continue to be an eential requirement for world development and human welfare.There is no other choice but to look for alternatives to present transport systems or to modify the technical and operational characteristics of related modes so that energy consumption and costs wil1 be reduced and environmental impacts can be kept at a minimum.Obviously, the development of transport demand will have to be controlled.
运输部门越来越无法满足需求，有效和公平地是，所有国家都必须应付在试图推动经济发展和社会进步的一个问题。能源供应约束、较高的资本和经营成本，往往与过度外汇组件和运输有关环境污染帐户在很大程度上对这一问题的严重性。但运输是并将继续是世界的发展和人类福利的基本要求。有没有别的选择，但寻找替代目前的运输系统，或修改相关模式的技术和业务特点，使能源消耗及成本失败会减少和环境的影响可以保持在最低限度。很明显，发展的运输需求将不得不加以控制。
Unit2
当在美国的方案最初是由移动2000构思超过10年前，我有四个主要功能区：先进的交通管理系统，先进的旅客informatior系统，商用车辆运营和先进的车辆控制系统。自那时以来的十年中，大多数的一般社会的关注一直集中在自动取款机和自动航站情报，AVCS定义已经扩大了与安全的另外AVCSS容纳安全预警系统没有实际的控制系统。
在许多方面有一个倾向，承担USDOT的形状和资源分配方案反映或者甚至其所有活动的范围确定在美国这个假设，特别是误导AVCSS的情况下，其中大部分活动发生在车辆的生产和供应业和最先进的思想比美国DOT，而内发生的状态点。该行业在研究和开发AVCSS产品AVCSS涵盖范围很广的用户服务和技术。这些通常是根据美国国家ITS体系结构（防撞纵向，横向防撞，视力增强，安全准备，预碰撞约束的部署和车辆自动操作）中包含的类别定义。然而，这并不甚至捕获，从不同范围内个人用户服务的合作和自动化水平出现的可能性的广度。的投资远远超过了由??政府投资。
警告系统能提供可闻，可见或触觉（触摸）线索，以提醒驾驶员潜在的不安全的条件下，驱动程序后，需要采取纠正措施，以避免危险。前向碰撞预警几年来一直在卡车上，主要是从伊顿- Vorad，卡车车道偏离警告系统已Iteris和SistWare宣布。短程警告OT停车危害也已为乘用车提供了好几年。
控制辅助系统提供控制自动驾驶功能的一部分，以协助纾缓工作量（例如，自适应巡航控制）的驱动程序，以提高安全性（例如，避免碰撞制动）。自适应巡航控制系统最近已成为在美国S（上TEW高档轿车奔驰S级，雷克萨斯i515人。 (~)。一辆巴士,25ft少(750万)长,由内燃机、容量超过十五人。 (~)。交通车辆总线:超过25ft(独立)长,通常被柴油发动机。 (_4)。公共汽车:运输汽车手推车推动电力线路从头顶。
(~表达公共汽车:交通公共汽车(柴油或电)和一个永久附semitrailer内部循环,乘客。 (~)。巴士或轻轨交通工具(轻轨):一个电推进轨道车辆运行在火车上单独地或者共享或semiexclusive让行。~ (~轨道车:一个电动汽车通常在推动的独家right-of列车——我道。我 (~)。通勤火车:一个标准的铁路客车和高密度阀座。这是可能的 推进(用电或柴油发动机)或设计以机车牵引。
(四)。轻轨交通(轻轨)指铁路服务至少部分共享或semiexelusive right-of1974), fatality rates show a long-term decline.The 3-year period 19761974, and imposition of the 55 mph speed limit, are seen to have had very temporary and limited effects on the generally upward trend of vehicle-miles driven and number of deaths.The trend in the death rate may or may not have stabilized at a rate below 3.5 per 100 million vehicle-miles or may be increasing again.由1925年的数据经过较长的一段时间，一般可以更清楚的看到长期趋势。1973年 - 1974年的燃料短缺，以及实行55英里每小时的限速，被认为对车辆里程数的总体上升趋势和死亡人数有非常短暂和有限的影响。死亡率趋势可能已经稳定在低于3.5起每1亿英里行驶里程，也可能没有，也可能会再增加。
Cause and Problem Areas 原因和问题领域
Collisions between motor vehicles are seen to be the largest single category of traffic fatalities.‘Non-collision’ accidents (many of which involve collision with a fixed object) are second.机动车之间的碰撞被认为是造成死亡的最大的单一类别交通事故。“无碰撞”事故（其中许多涉及与固定物体碰撞）居第二位。
Identifiable problem areas in highway traffic safety include: (1)Pedestrian-vehicle conflicts (2) Vehicle-vehicle conflicts (3)Interactions of differently sized vehicles (4)Inadequate or impaired driving ability (5)Railroad-highway grade croings (6)Inadequate communication with the driver (signs, markings, signals), and between drivers (7)Deterioration of physical plant (reduced maintenance on highways and bridges) (8)Roadside safety hazards 公路交通安全中可识别问题领域包括： （1）人车碰撞 （2）车车碰撞
（3）不同大小车辆相互碰撞 （4）驾驶能力不足或受损 （5）铁路与公路地面岔口
（6）与司机沟通不足（标志，标记，信号），以及司机之间沟通不足 （7）物质设备的恶化（公路和桥梁的维护减少） （8）路边的安全隐患
About 18% of the motor-vehicle-related deaths are pedestrian deaths (about 8000 in 1978).Intersection accidents account for the major proportion of urban accidents.与机动车辆有关的死亡人数的约18%是行人死亡（1978年为约8000）。 交叉口事故占了城市事故的大部分。
The trend toward smaller automobiles and larger trucks has created a major problem on the highways, a problem that is aggravated by increases in motorcycle use; on many roads, bicycles and mopeds are added to the problem.小型汽车和大型卡车之间发生事故的趋势已经成为了公路上的一个主要问题，一个由摩托车使用而加剧的问题;在许多道路，自行车和轻便摩托车被补充到这个问题中。
A majority of accidents are still attributed to ‘human error’, or driver impairment through the use of alcohol or other drugs, even though it is clear that only minor advances can be expected in controlling this problem.At the same time, improvements in vehicle design and control, and highway design and control measures, have not been exhausted.大多数事故的原因仍然是“人为错误”，或司机因为酒精或其他药物的使用造成意识模糊，即使这很明显，但控制这一问题的进展很小。与此同时，汽车设计和控制，以及公路设计和控制措施方面的改进尚未做到尽头。
The railroad-highway grade croing problem is one that should be clearly understood by transportation engineers and treated as an illogical intersection of two vastly different modes.Although it is economically impractical to eliminate all grade croings within a brief time period, grade separation is the only positive engineering solution available and should be scheduled over a reasonable period, Other treatments for rail-highway grade croings are interim solutions at best.铁路-公路地面交叉口是一个应该被交通工程师清楚地了解，并被以两个截然不同的模式不符合逻辑的交叉对待的问题。虽然在经济上短暂时间内消除所有地面过路口是不切实际的，立交是唯一积极合理的工程解决方案，并应在一段合理的时间内落实，铁路-公路地面交叉口问题的其它解决方案最好作为临时解决方案。
Poorly designed, placed, and maintained signs, poorly timed signals, and poorly maintained or nonexistent markings still abound in many areas of the country.It was stated in 1979 that bridges in the united states ‘are collapsing at the rate of one a day’.And by 1979, 12 years after the U.S.House of Representatives\' Subcommittee on Federal aid Highways hearings pointed out the roads if le-hazards or ‘booby-traps’ problem on high speed roads, deaths attributable to this kind of single-vehicle accident were again approaching 17,000 per year.设计、放置、标志维护不当，时机不当的信号，维护不力或不存在的标记，在该国许多地区仍然比比皆是。有人说在1979年，在美国桥“是以每天一个速度塌陷”。而到了1979年，12年后，美国众议院小组委员会听证联邦援助公路的道路指出，如果乐危害或\'诱杀装置对高速道路的问题，这个死亡人数的单一种是车辆事故再次接近每年1.7万。
Unit 19 Driver Behavior and Accidents行为与交通事故
Some types of improper driving as related to accidents can be the results of either willful or inadvertent errors.Unfortunately, it is not easy to discover which type of behavior has caused an accident.部分交通事故的发生可能是由于司机故意或者疏忽造成的，但是不幸的是，要明确到底是哪种情况引发了交通事故却并不容易。
An October 1970 report by the U.S.Department of Transportation deals with this difficult problem and concludes: \"the negligence law usually treats \'driver error\' ?both avoidable and unreasonable, and imposes liability pursuant to an objective standard to which all drivers are held.But a review of the available research indicates that a significant gap exists between the standard of behavior required by the negligence law and the average behavior normally exhibited by most drivers.\" 根据1970年10月份美国运输部的一份报告，过失罪通常将司机的错误归为能避免的且非理性的错误中,并且依照所有司机都遵循的标准将法律责任强加进来。但是对这个探究的一篇评论指出，在过失罪所必需的行为标准与大部分司机所表现的一般行为之间存在明显的差别。
The report also says: \"You will note that the standard of care required is that exercised by a person of reasonable and ordinary prudence, rather than that exercised by a person of extreme caution or exceptional skill.While exceptional skill is to be admired and encouraged, the law dose not demand ?it as a general standard of conduct.\" ? 报告还说，注意的标准是一个人只要理智并且达到普通的审慎标准就行了，而不用非常小心且具有超高的驾驶技术。尽管娴熟的驾驶技术是法律提倡的，但是法律并不将此作为衡量的普遍标准。
Many programs of driver improvement seem to be based on an aumption of willful misbehavior and therefore concentrate on the multiple violator and accident repeater.However, studies by Campbell show that there 13 little evidence to support this position.Most accidents involve drivers with good records who have not had any previous serious crashes.In other words, the old concept of the \' accident-prone\' driver is not supported by the facts.? 很多提高驾驶技术的课程一般都以司机的错误是有意的为假设，因此将重点放在多次违规和事故的重复上面。但是坎贝尔的研究表明没有足够的证据支持这个假设，很多驾驶记录优良的司机也会出事故。或者说原来的易出事故的司机的假设是不成立的。
Each year traffic accidents seem to be distributed among the states m about the same proportion per millions of vehicle-miles driven.Raw numbers of fatal crashes occur more frequently during the summer and fall when there is more travel.These facts all seem to point to the conclusion that the more driving we do, the more the chance of an accident occurring increases, the more do occur.This would seem to argue for the major role of change in the distribution of fatal crashes.Undoubtedly, chance factors are acting, but each accident was caused and therefore could have been prevented.?每年交通事故的分布基本集中在特定的州并且比例相对固定，致命的事故通常发生在旅游旺季夏天和秋天。以上事实都证明了司机开车越多，发生事故的概率就越大，事故次数也就相应增多。这似乎说明改变在致命事故中发挥的作用，但是毋庸置疑的是，机遇因素也同时在发挥作用，但是每件交通事故也可以因此避免。
Since the majority of motor vehicle accidents occur in daylight on dry roads with sound vehicles, the causes seem to be with the drivers and the ways in which they interact with the roadway.The more that is understood about drivers, the more likely are traffic control and remedial efforts to be succeful.Burg deal with this question and presents the following conclusions: ??? 因为大多数机动车事故发生在白天干燥的路面上，且一般都是好车，所以原因或许是司机本身和路面的问题。对司机的了解越深，交通控制和补救措施越成功。伯格研究了这个问题，并且得出了如下结论：
（1）Biographical descriptors: A justification exists for differential licensing for both young and old drivers, and implementation of such a program is feasible.Not feasible, however, is differential licensing on the basis of such factors as marital status, education, or ?annual mileage, although research results would suggest such a move.（1）传记体叙述: 分别为年轻司机和老司机发不同的驾驶执照是公正合理的，实施这样一个方案是可行的。然而，颁发不同驾照建立在诸如婚姻状况、教育程度或者年行驶路程等因素的基础上却是不合理的，尽管报告里建议这样做。
(2)Chronic medical conditions: There is sufficient evidence relating certain serve medical conditions to accidents to suggest that short-term licensing of such individuals might prove beneficial.However, final action of this sort should not be taken without confirmation of present findings through a carefully controlled study （2）长期医学状况：大量证据表明，将确定的医疗条件服务与因持短期驾照的个人造成的事故相联系被证明或许有益处。然而，在没有认真可控的研究证实现有发现的确定性之前，这个说法走不到最后一步。
(3)Hearing: Present evidence suggests that the deaf driver may be at a disadvantage, and that special training programs and/or special aids might be of benefit; however, additional research again is needed before action is warranted.（3）听力: 现有证据表明失聪司机会出现不利状况，特殊训练方案或者特殊救助或者会有益处。然而，在行动有足够保证之前仍然需要额外的研究。
(4)Lo of limb; There is no evidence to justify taking any action in this area.（4）肢体残疾; 没有证据证实在这一领域采取了行动。
(5)Vision: Research results indicate that vision is indeed related to driving.However, the magnitude of the relationship appears to lie small, and the question of practical significance arises; however, it is interesting to note that Shinar found that \"nighttime accident involvement is related to poor visual acuity under nighttime levels of illumination, but unrelated to visual acuity under high (daytime) levels of illumination .\" （5）视力:研究结果表明视力确实和驾驶关系密切。然而，两者关系的密切程度出现缩小的形势，而且实践的重要性问题逐步扩大。然而，注意到Shinar的这一发现挺有趣：夜间车祸与低于夜间照明水平的低视觉敏锐度有关，但是与低于高（白天）照明水平的视觉敏锐度无关。
?Burg states: \"How much improvement in the traffic accident picture can be effected by more effective vision screening? By the same token, of what value are present licensing techniques such as written examination and driver tests? These are questions that have no clear-cut answers, for definitive research has yet to be done, and other factors, such as \'face validity\' and \'tradition ”serve to confound the iue .伯格总结说：“如果视觉甄别更有效能在多大程度上降低交通事故呢？同样地，现行的笔试和路考驾驶技术的测试又有多大价值呢？有的问题并没有明确的答案，还需要研究来证明，另一方面，其他因素，例如表面有效性和传统可以帮助解释这个问题。”
Drivers can become involved in accidents even as innocent victims and yet be included in some records.Because of legal implications, many such records do not distinguish the \'at fault’ driver from those not at fault, which makes research in group behavior very difficult.Therefore, care must be exercised when examining studies of driving accident records to know what criteria were used.司机有时候即使作为无罪的受害者也会卷入事故中或者被记录在案。因为法律涉及，许多记录并不区分有过错的司机与无过错的司机，这使群体行为研究变得非常困难。因此，必须谨慎关注驾驶事故研究，以了解使用的什么准则。
第20单元 单向交通
尽管大多数街道和公路的设计用于通过双向交通， 增加交通流率的同时也增加了车辆和行人与车辆之间的冲突，由此产生的交通拥挤及事故往往使人们考虑到用单向交通。主要的活动中心，如中心商务区的城市拥有一大批高交通，密集的交叉口、因为考虑到交通信号时间和提高街道的通行能力单行道经常被采用。发展中的新的活动中心如购物中心、运动场馆、工业园等， 单向交通方式经常被用于改造原始街及其他交通计划。
单向街道一般运行在以下三种道路情况之一： ①街道上的交通在所有时间都保持一个方向移动。
②单向车道通常是单向的，但在某些时候可能调整以提供其它方向上的使用，即主要的流动方向相反的方向。
③一条街道通常情况下进行交通繁忙的双程行车，但在某一方向流量较重时，通常运用单向交通。单向交通通常被设在交通流较大的方向上，例如在早高峰时单向交通设在某一个方向上。在晚高峰时设在相反的方向上，其他时段相同用双向交通运作。
利与弊
单向交通通常用于减少交通挤塞，增加街道网络的能力。同样单向交通也会影响安全和毗邻的土地的使用。
(1) 对性能的影响
在城市双向街道上交通冲突和交叉口延误是导致的交通挤塞及旅行时间减少的一个主要原因。单向交通中反向交通并不会影响左转弯的进行。此外，特殊的道路宽度是完全会被使用的解决方案。利用单向交通的方案，可增加高达50%的道路通行能力。
实施单向交通后提高了道路通行能力,也同时实现了双向交通不能允许的临时或全天的路边停车。更加有效的信号配时还可以增加街道的通行能力能力。
(2) 对安全的影响 在交通信号控制的单向交通的主要路口行人和车辆安全通过性与在其他交叉的街道和车道通过时存在差距。此外，驾驶员和单向交通中的行人仅仅需要注意单方向行进的交通。
许多研究表明双向交通改单向交通因为驾驶技术造成的意外事故减少 10 %至 50%。在某些情况下，更减少了特定类型的意外。驾驶员为了找到空隙停车或为了转向进入适当车道而采取的不适当的交织会增加路段上的轻微交通冲突数。然而，单向和双向操作之间的过渡地区经常会发生危险，需要特别的交通控制方案。
(3) 对交通流的影响
使用单向交通的主要原因是，改善交通运作，减少交通挤塞。改善运行条件、行驶速度和安全程度，当然这取决于以往的运行情况。一般情况下，旅行时间可以缩短10% 至 50%，交通事故率减少 10% 到 40%并轻微的增加整个交通系统的运作能力。一些改善交通运行的方法应该被采用与以下的消极方面取得平衡：
①驾驶必须旅行额外远才能到达目的地。这浪费时间和燃料。
②在单向交通中，特别是如果网络几何是不规则的并且没有特别明确标记和信号标志的道路上外来车辆可能容易弄混。
③如果道路被强制的由单向改为双向，长途运输业可能会因此受到不利的影响。在一条狭长道路上的旅行，可以走到最近的公共汽车站，步行前往并采用公共交通的人数会增加。
④紧急通行的车辆，如消防车，可能需要采取更为迂回的路线到达其目的地。但是通过，紧急车辆将进入单向系统之前的信号控制，即实行人工干预对单向交通上的车辆放行以使紧急车辆快速进入下一个十字交叉口，这样会在某种程度上减轻紧急车辆在道路上浪费的时间。
(4) 对区域经济条件的影响
改进的交通运行，提高的安全性通常会对相邻的土地使用者和公众产生广泛的经济利益。然而，规划单向交通系统时，特别是涉及到商业街道时，商家可能会认为实施单向交通后将会影响到他们的正常营业，因而交通工程师们应该预计到他们会反对实施单向交通。
但在美国各地的研究一般而言会反对对此类造成影响的索赔。此外，一旦实施了单向交通系统之后，许多原来反对实施单向交通的商家却成了忠实的拥护者。单向交通很少会再次更改回双向交通，除非主要新公路设施建设使单向道路系统不必要继续运行。
虽然很多地方经济和环境因为一个接一个的地区改为单向交通模式而受到影响，密歇根州公路部门的深入研究却揭示了一些有趣的结果。
① 大多数住在单向交通道路周边的居民都对单向模式表示不满意，就是在此类地区存在着最大的交通不满。
②在调查区域内的居民，从感觉上或者态度上抵触情绪的减轻至少是因为其中有些人的居住地远离单向交通区域。
③长期定居的居民认为单向交通的转换会造成财产损失，而且从环境角度来看，会造成地区环境满意度下降。不过，市场分析结果显示最大的住宅物业价值增加出现在低的交通量转换的最大程度环境不满的街道上。
④ 没有迹象显示单向街道对商业活动的负面经济影响。生意失败的次数自单向转换后大幅减少。
第21单元交通管理
目标
交通管理起源于这样一种需要，那就是在预算有限的情况下，以最少的新建工程项目，最大限度的提高现有道路网的通行能力。这种方法，经常被看作为快速修复、必需的创新解决方式和新的技术发展。许多技术设计对传统高速公路工程和设计构思以及有损交叉口设计采纳均有影响。引导行人穿越道的控制标志，不仅是改善在拥挤道路上的安全而是要通过不让行人支配穿越地点来改善道路的交通容量。
最近（交通管理的）重点已从简单的通行能力改善转移到减少事故、限制需求、公共交通优先、环境改善和保障步行者及自行车骑行者的安全、自由通行等方面。
需求管理
有一种这样态度上的重大转变：就是不再支持高速公路在容量上不受限制的成长。这种在城镇和都市的潜在毁灭和对乡间的环境损害使其不被大多数人们接受。交通管理使其在很大程度上极大化公路网的容量，然而需求量和拥挤仍在继续的增加。
公路主管当局认为他们无法授权提供资金给大量的新建造。很显然，在可预见的将来，资源将不能提供私人的无限制的车辆交通量增长。单独的交通工程是不能够提供充足的高速路容量的即使是限制很多新的构造。
一种需求管理的方法已经受到相当多的兴趣并且研究的是拥堵的管理。这是车辆被收取额外费用作为他们使用拥挤的道路空间的地方。新技术以智能卡的形式需要确保系统车辆监别是可实行、公平的。调停外部或者非局部的车辆措施也是不可或缺的。影像分析已经达到了能被用作可以完成这个目的的水平。
工程检测
交通工程师有一系列能被应用于目标的巨大措施。这些目标包括：容量增强；事故校正；环境保护和增强；服务的修护和提供出入口；提供援助给行人和骑脚踏车的；协助公交车或电车道驾驶人；提供伤残人士的设施；管理路内和路外的停车。
大多数交通容量问题都在道路交叉口发生。市区的道路交叉口，不仅是行人和自行车活动的重要的中心点，而且也通常是公共交通立交桥的所在地。由于各种相互矛盾的需求，这并不令人感到惊讶，市区交通事故的三分之二发生在道路交叉口。给一个特殊的地点选择一个合适的交叉口设计方案可能很困难。一些设计，像是绕道的，虽然能显著地减少车对车事故的严重性，但是却增加了骑自行车的危险性。在一些行人及全循环设施和公交优先措施的交通信号情况下可能还降低了整体的交通处理能力。
细致的道路空间的分配来分离交通流到专用车道能减少混乱而且限制事故。专用车道可能含特别的车辆道，像是回头车道和公共汽车优先车道和左转或右转车道。
禁止转弯和单行道的实施能减少潜在的冲突和事故发生。这些措施能被用于履行受保护的行人或者循环叉道以及简单交叉口的布置。当单行道方案被考虑时，须严格谨慎以使得单行道的方案可以让驾驶者能够自由的不受对向其他的交通工具的影响以加快行驶速度。
道路点的封闭常被用来简单化交叉口和高速公路布置以及除去转冲突。这种连续的人行道也能改善徒步者的安全以及提供公共汽车停车站的空间，周转率，人行道，和硬软式风景设计。
从常规交通中封闭一大段路可以形成步行商业街。这种方案可能很难设计和改进，因为公共汽车，急救部门车辆，驻存/所有人和服务车辆的设施都必须被考虑。
车道狭窄可以用来限制容量，或者车辆速度，而且减少停车和行人穿越道距离。
所有成功的交通工程方案的关键是视觉的诱导由道路的视觉诱导提供给一个有优先权的使用者清晰地道路指示。
交叉口类型
有许多不同的详细划分的交叉口类型，但是它们可以分为五种基础类型：不受控制的非优先次序交叉口；优先次序交叉口；圆环型；交通标志；立体交叉。
路标
过高的对道路系统的重要的路标作评价是不可能的。在一些事例中，道路标线只强调公路的设备布置和引导道路使用者到安全的行驶路线。在许多情况下，方案的成功全部依赖于道路标线所发出的视觉的信息。
交通标志
交通标志区分为四个类目；警告标志；禁止标志；方向指示标志；其他指示标志。
警告标志提供一些危险因素的信息，像是联系络点、方向的改变，车道宽度，倾斜、低洼，曲面桥，道路施工等等给道路使用者。
禁令标志提供一些必须遵守的信息，例如停车、让路、禁止转弯、强制转弯、禁入、单行线、车种限制、车重和车宽限制、停留及装载限制以及速度限制等。
方向的指示标志提供关于工作路线的确定和重要地点的吸引，像是铁路车站，航空站等等的信息。 其他指路标志提供关于人行道和其他停车方案，传统位置点，调查报告测点等等信息。交通标志时常连同道路标线安装在一起。
Unit 23 Parking 停车位 Parking is a commodity that is subject to the basic laws of economics.Thus, for example, if a parking policy is developed which results in a reduction in the number of long-stay parking spaces in a town centre, then a new equihbnum point will he established which will result in a higher pnce to the consumer for parking; this higher price, in turn, will make it le attractive to make the journey-lo-work trip to the town centre by car.Thus parking policy affects how people will travel and good parking management and control can lead to some or all of the following: higher car occupancies, decreasing person-trips, faster travel times and le travel delays, greater public transport usage, decreasing congestion, and reduced air and noise pollution.Traffic and parking: some aociated effects
停车是一种基于经济学的基本规律商品。因此，例如，如果停车措施政策发达，结果会导致长住在市中心的泊车位的数目减少，然后新的平衡点确立，并将导致消费者花更多的钱去停车； 这更高的价格反过来将使乘车去市中心工作失去吸引力。因此停车政策影响到人们如何出行，好的停车管理和控制能带来下列一些活着全部效果：提高车辆占有率，减少出行时间和延误，增加市区公共交通使用率，减少堵塞和降低空气和噪声污染。
交通和停车：相关的影响 (1)Aesthetics An environmental \'disamenity\' which receives little attention is the aesthetic deterioration often aociated with the parking of vehicles.（1）美学
通常与车辆停泊相关而且很少收到注意是审美的恶化。
(2)Busine, acceibility and parking Cconmercial interests consider that they are directly affected by the parking situation and, even in this day, many merchants and busine people in city centres tend to regard packed kerbs a neceary visual evidence of trade prosperity.（2）业务、辅助功能和泊车位
商业团体考虑他们直接受停车的情况的影响，并在即使在这一天，许多商家和城市中心区的商界人士倾向于把利用这种可见的具有贸易繁荣性质的路缘。
Accidents 事故
Although vehicles parked at, or manoeuvring into or out of, kerb parking spaces can be an important cause of accidents, the number of studies which have been carried out in order to produce an understandable and accurate description of the role of parking in accident occurrence is relatively few.虽然车辆停车，或操纵进入或离开，路边停车已是一个事故的重要原因，被做过研究停车在交通事故中可以理解的准确的调查的数量是相对较少的。
Surveys 调查
Parking surveys are carried out in order to obtain the information neceary to provide an aement of the parking problem in the area(s) being studied.The objective of any suchstudy is to determine facts which will provide the logical point of departure in relation to indicating parking needs.Commons to all types of parking studies, whatever their scale, are parking supply and parking usage surveys.停车调查时为了收集对研究区域的停车问题惊醒评估时所必须的信息。任何此类研究的目标是确定这些将提供适用于指示的停车需求的逻辑起点的事实。所有类型的停车研究，无论其规模，都是停车位供应和停车使用情况的调查。
(l)Parking supply survey Parking supply surveys are concerned with obtaining detailed irrformation regarding those on- and off-street features which influence the provision of parking space, the existing situation with regard to parking space, and how it is controlled.A typical survey would require an inventory of the on-street accommodation, and of all off-street car parks and parking garages serving the traffic area heing studied.Whether the survey area involves the central area of a town (which may be broadly define as the area in which all streets have busine frontage), or a suburban shopping area, or a hospital or university, it should also include the surrounding fringe area where vehicles are parked by persons with destinations within the survey area.(1)停车位供应调查
停车供应调查时着重于获得那些影响提供停车空间的道路的详细信息。停车空间的现状以及如何去控制。一个典型的调查要求获得道路的容量.远离道路的停车场以及服务于被调查地区汽修厂详细清单。无论调查区域是否包括市中心区（通常可能会被定义为所有商业街都具有商业前沿的地区），或者一个郊区购物地域，或者医院或者大学，它应当包括被调查区域内人们用来停车的边缘地区。
(2)Parking usage survey The parking phenomenon is very much based on the law of supply and demand, whereby supply is the total number of spaces available within a designated area, and demand is the desire to park based solely on the location of the trip destination.However, unlike the true supply and demand situation, there ts a third variable-usage-aociated with parking which reflects the desire to park close to the desti-nation, but within the limitations imposed by the available supply, as well as the desire to park reasonable cost.In other words, demand is a constant, reflecting the desire to park at the trip destination, whereas usage is a variable that depends upon the conditions at the terminal area and upon the characteristics of the trip as well as of the trip-maker.(2)停车场使用情况调查
停车现象很大程度基于供应和需求的规定，即供应是一个指定的区域内可用的空间总数及需求是一种在旅行目的地停车的渴望。然而，与真正的供应和需求情况不同，与停车相关的第三种情况即反映渴望去停在目的地周围地区而收到可获得供应的限制以及一种渴望合理的停车消耗。换句话说，需求是一个常量，反映渴望停在旅行目的地，而适用情况是一个变量，它依赖于目的地条件和旅行的性质以及要旅行的人。
If the parking supply is in exce of the parking demand, then the true demand can he determined by means of a parking concentration survey-usually carried out in conjunction with q parking duration survey .If the parking supply is le than the demand, then an indication of the demand may be obtained by means of a direct-interview parking survey; however, the true demand, which might include\' suppreed\' vehicles not able or willing to find parking within the survey area, can only be properly estimated from comprehensive land use/transport surveys of the nature noted previously in this text.如果停车位供应过剩，真正的需求量取决于停车浓度调查和停车时间调查。如果停车位供应是小于需求，然后相对值的需求可能通过直接停车调查获得；但是，真正的需求，其中可能包括被禁止的不能或不愿意在统计调查区域找停车的地方车辆，只能够从综合土地使用及以前文本指出的交通调查的性质来正确估计。
Concentration survey 停车占有率调查
The purpose, of a concentration survey is to determine not only where vehicles do park, but also the actual number parked at any given instant at all locations (on- and off-street) within the survey area.The street phase of the survey is usually carried out by dividing the survey area into * beats\' , each short e-nough to be toured on foot or by car within a pi^eterrnined time interval, biformation regarding the numbers of vehicles parked (legally and illegally) at each street and alleyway location is then noted on prepared forms or spoken into a tape recorder for transcribing at the end of the day.Each beat normally forms a closed circuit so that no time is lost by the observer( s) in returning to the starting point for succeive inspecti6ns.停车占有率调查的目的，不仅要确定在哪里停车还要确定在任何给定的时刻调查范围内所有地点的实际泊位数目(对内和路旁）。调查的街道阶段通常把它分成几个辖区，每个辖区要能够在步行范围内或乘车能在预订时间内到达。关于停靠在街道和胡同里车辆(合法和非法)数目的信息在每一天工作后，要用表格或者口述录音的方式记录下来。每个辖区通常形成闭合区域以至于最后通过与起点核对没有遗漏的地方。
Duration survey 连续调查
The primary purpose of a duration survey is to determine the lengths of time that vehicles are stored within the survey area.In so doing, data normally collected during a concentration survey can also be collected (in eentially the same way, in the case of the on-street survey) during the.duration survey.持续时间调查的主要目的是确定车辆停留在在调查范围内的时间长度。这样做，通常浓度调查过程中收集的数据也可以在持续时间调查过程中收集 (方式基本上相同，在对街道调查的情况下）。
Parker interview survey 停车访问调查
This, the most expensive;—and comprehensive^
—of the parking surveys, normally involves interviewing motorists at their places of parking and questioning them regarding the origins of the trips just completed, the primary destinations whilst parked, and the purposes of the trip.Particulars regarding parking duration and concentration may also be gathered during this survey and, if required, information may obtained regarding the number, sex and age of each vehicle\'s occupants.这，最费时— 最全面— 的停车调查，通常包括在停车地点访问驾驶者和提问他们关于刚完成的形程起源地，停车的主要目的地和旅行的目的。关于停车持续时间和停车占有率的资料也可以在这次调查的过程中收集，如果需要，可获取车辆拥有者的数量.性别和年龄的信息。
