交通运输专业英语课件 (Drivetrain)
交通运输工程英文课件Lecture 15
CAPACITY: CONCEPT AND DEFINITION
Capacity: Definition Capacity of a transportation facility is defined as the maximum number of vehicles, passengers, persons or the like, per unit time which can be accommodated under given conditions with a reasonable expectation of occurrence. The Highway Capacity Manual (2010) defines the capacity as the maximum hourly rate at which vehicles or persons can be reasonably expected to traverse a point or a uniform segment of a lane or roadway during a given time period, under prevailing roadway, traffic and control conditions. Several observations can be made from the above definition. Although capacity is the maximum hourly rate, in many situations the 15 minute equivalent flow rate is expressed as the capacity.
LEVELS OF SERVICE: CONCEPT AND DEFINITION Levels of Service: Concept and Definition An operation related question is, what is the performance level of the system at various operating conditions. Or in other words, how good is the operation of the traffic facility. Levels of Service (LOS) analysis tries to answer this question which is essentially a qualitative analysis. Level-of-Service(LOS) of a traffic facility is a concept introduced to relate the quality of traffic service to a given flow rate. Level of Service concept is introduced by HCM to denote the level of quality one can derive in a facility under different operation characteristics and traffic volume.
交通运输专业英语
Lesson 1 Fundamentals of AutomobileToday’s average car contains more than 15,000 separate, individual parts that must work together. These parts can be grouped into four major categories: engine, body, chassis and electrical equipment (Fig. 1.1).目前大多数汽车由超过15000个各自独立的零部件组成，这些零部件必须一起配合工作。
这些零部件可归为四大类：发动机，车身，底盘和电器设备。
1 EngineThe engine acts as the power unit. The internal combustion engine is most common: this obtains its power by burning a liquid fuel inside the engine cylinder. There are two types of engine: gasoline (also calls a spark-ignition engine) and diesel (also called a compression-ignition engine).发动机作为动力单元。
内燃机是最常见的一种发动机，这种发动机通过在其内的气缸中燃烧液体燃料来获得动力。
有两类发动机：汽油机（也叫火花点燃式发动机）和柴油机（也叫压燃式发动机）。
Both engines are called heat engines; the burning fuel generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the transmission.Both engines are called heat engines; the burning fuel generates heat （which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the transmission.）两种发动机均被称为热机，由燃烧的燃油产生热，引起气缸内气体的压力升高，并输出动力使连接到传动系的轴旋转。
《城市轨道交通专业英语》 Part4
标
Unit12 Vehicle
题 八
The bogie includes frame, axles, electrical motors, suspension springs, wheels and brake system.
There are several manufacturers producing metro vehicles globally. The well known foreign brands are Simens, Bombardier, Alstone, Rotem, Toyo GTO, Mitsubishi and so on. In China, there are two groups representing six companies.
Peter: Lin, do you know we just have some new metro vehicles arrived for this line?
Lin: Really, how many? Peter: 4 trains. Every train has 6 cars and trailers. Lin: What are the differences between cars and trailers? Peter: I have no idea, I am going to fce Awareness
题 八
Lin: I hope we can get more trains with more units for this line. Peter: Why? Lin: Do you know that the extended line will be in operation by the end of this year? Peter: Yes, that is why we have those trains here, they are ready for the upgraded line. Lin: Have you noticed that the traffic of this line is increasing recently? Peter: Yes, I have. You are right. We do need more trains with bigger size. Lin: Let's go to find out what size they are.
交通运输工程英文课件Lecture 17
Capacity and LOS: Signalized Intersections
Lane groups: are those that serve traffic in the same direction
and have more-or-less homogeneous traffic flow conditions.
City of Ottawa uses a base saturation flow, S0 = 1,800 pcphgpl
Capacity and LOS: Signalized Intersections
Base saturation flow rate for a particular lane group: s = s0 N fW fHV fg fp fbb fa fLU fRT fLT fRpb fLpb where s0 = base saration flow rate, 1800 pcphgpl (City of Ottawa) N = number of lanes in the lane group fw = lane width adjustment factor fHV = heavy hevicle adjustment factor fg = approach grade factor fp = parking factor fbb = bus-blockage factor fa = factor for area type fLU = lane utilization factor fRT = right turn factor fLT = left turn factor fRpb = pedestrian-bicycle adjustment factor for right turn fLpb = pedestrian-bicycle adjustment factor for left turn
交通运输专业英语 (3)
Lesson 1 Body
1.1.3 Integrated or Monocoque Body Structure
This kind of body structure has no frame. In this case the body is the base to install all the systems and bears all the loads from them. In order to get rid of the rather heavy frame, almost all the cars and most of the buses choose the integrated body structure.
Lesson 1 Body
1.1.2 Combined Body-Frame Structure
The maLeabharlann n feature of this kind of body structure is the connection of the body and the frame through stiff joints such as welded, riveted or bolted connections. In this case the frame is the base to support all the systems and bears most part of the loads from the working systems. The body is taken into account of helping the frame and sharing a part of the loads.
Lesson 1 Body
chapter 5 transmission 汽车服务工程专业英语 教学课件
Drive pinion 主动轮
Automotive Engineering English
Lesson 2 Basics of Four-stroke Cycle Engine
Review 4: List the Gear Types of final drive.
Spur Gear （直齿圆柱齿轮）
Automotive Engineering English
Lesson 2 Basics of Four-stroke Cycle Engine
Review 1: What’s the function of drive shaft and UJ?
To transmit the drive from the transmission mainshaft to the final drive pinion; To have some allowance for motion between the final drive and transmission.
9.release bearing and release sleeve
10.16.return spring
11.clutch shaft (gear box primary shaft)
12.clutch pedal
13.release fork
14.clutch linkage
Automotive Engineering Englis1h5.adjustment fork
Automotive Engineering English
Lesson 2 Basics of Four-stroke Cycle Engine
Single( reduction) final drive(单级主减速器)
交通运输专业英语unit4
In certain situations, exhaust system leaks can also lead to death.
Proper vehicle inspections can address exhaust system issues before these problems occur.
1.2 Exhaust system
Carbon monoxide from diesel emissions can be dangerous. Prolonged exposure to concentrations of CO can lead to headaches, shortness of breath, nausea, dizziness or light-headedness. These symptoms adversely affect a driver’s ability to safely control a commercial motor vehicle.
A cause of the fire was determined to be a hole in the fuel supply line, resulting in a fuel leak.
汽车专业英语课件-1 cha
精选课件ppt
11
Chapter 1 General Information
1.1 Basic Parts of Automobile
2. Body
An automobile body (Fig.1-2) provides a protective covering for the engine, passengers, and cargo. The body is designed to keep passengers safe and comfortable. The body styling provides an attractive, colorful, modern appearance for the vehicle. It is streamlined to lessen wind resistance and to keep the car from swaying at the driving speeds.
Automotive Marketing
and Service
Automotive Design and
Manufacturing
精选课件ppt
3
Chapter 1 General Information 本章学习内容、目标和重点难点
本章学习内容
1. Basic Parts of Automobile 1. Classification of Automobile
设 计制造
学习目的
1.打好基础：首先掌握必要词汇，熟悉并巩固语法与专业知识，开 阔眼界；学好本门课程，对考研亦有一定的帮助
2.掌握翻译技巧，提高翻译水平，较熟练笔译专业资料，解决生产 实际中的问题
3.阅读本专业领域的国外资料，了解和掌握汽车的发展动态和前沿
城市轨道交通专业英语
城市轨道交通运营管理专业专业英语ListListChapter 1: Development of Urban Rail Transit Speeds up in China (3)Chapter 2 Rapid Transit (12)Chapter 3RAIL TRANSIT IN NORTH AMERICA (23)Chapter 4 The Railroad Track (40)Chapter 5 General Vehicle Description (45)Chapter 6A TP Transmission and Moving Block (53)Chapter 7Control of Railway Operation (62)Chapter 8Train Station Passenger Flow Study (74)Chapter 9Metrocard Fare Incentives (81)Chapter 10 Audible Information Design in the New York City Subway (86)Chapter 1: Development of Urban Rail Transit Speeds up in China With the development of urban rail transit, on the one hand, it is promoting the process of urban modernization, alleviating congested traffic in cities, and narrowing the distance between time and space. On the other hand, it changes the way people travel, accelerates the pace of their life and work, and affects the quality of life.The state of urban rail transit reflects a country's comprehensive strength and is a symbol of a city's modernization level. At present, rail transit system is available in 135 cities in nearly 40 countries and regions. In cosmopolitan cities, accounting for a proportion of 60 per cent - 80 per cent, rail transit has become the leading means of transportation in these cities. Yet so far, in Beijing, Shanghai, Tianjin and Guangzhou, etc., rail transit accounts for less than 10 percent in the cities total traffic capacity.Urban rail transit offers comprehensive advantages, like small land occupation, large traffic volume, high speed, non-pollution, low energy consumption, high safety and great comfort. With most facilities being installed underground and the operation going on underground, subways require very limited occupation of land, and do not compete with other means of transportation for space. Urban light rail, trolley bus as well as suburban rail and magnetic suspension train are basically railways, which makes it possible to make the most of land resources.Urban rail transit system offers immense transport capacity. During rush hours, the maximum unidirectional transport capacity may reach up to 60, 000- 80, 000 person-times per hour, which is unmatchable to other means of transportation. The hourly traveling speed of rail transit generally exceeds 70 kilometers-100 kilometers, offering high punctuality. Moreover, mostly being hauled by electric locomotives, rail transit requires low energy consumption, and it causes little pollution to cities. Therefore, it is called "green transportation".From a macro perspective, urban rail transit plays an important role in improving the structure of urban transport, alleviating urban ground traffic congestion, and promoting the utilization efficiency of urban land.Nevertheless, compared with other means of transportation, rail transit has some drawbacks, like long construction cycle, heavy initial investment, slow withdrawal of funds and poor economic benefits in operation. For example, currently the building of subway costs some RMB500 million-700 million per kilometer; urban light rail and magnetic suspension train, RMB200 million-300 million; trolley bus and suburban rail, about RMB100 million.In China, rail transit dates back to the late 1960s, when the first subway was built inBeijing. That was nearly one century later than developed countries in the West. However, since it made its debut, urban rail transit has helped ease the immense pressure caused by urban traffic congestion and brought great convenience and comfort to passengers. Take Beijing for example. Currently, subways provide a transport volume of approximately 1.5 million person-times per day. Without subways, the traffic congestion in this city would simply be inconceivable.At present, rail transit has evolved from the startup stage to a period of stable, sustainable and orderly development in this country. In China (excluding Hong Kong and Taiwan), the length of subways completed totals 193 kilometers; project urban rail under construction, 334 kilometers; planned urban rail, 420 kilometers. Among big cities with a population of over 2 million, those that already have or are building urban rail transit include Beijing, Tianjin, Shanghai, Guangzhou, Dalian, Shenzhen, Wuhan, Nanjing, Chongqing and Changchun. Now, seven cities have announced or are still working on their plan to build rail transit: Chengdu, Hangzhou, Shenyang, Xi'an, Harbin, Qingdao and Suzhou.According to plan, by 2008, there will be thirteen rail transit lines and two spur lines in Beijing, with a total length of 408.2 kilometers. In Shanghai, there will be 21 rail transit lines, totaling more than 500 kilometers in length. During the Tenth Five-Year Plan period, the total length will hit 780 kilometers. In Tianjin, there will be four subway lines, totaling 106 kilometers. That, coupled with 50 kilometers of suburban light rail and one loop subway 71-kilometers set aside, will bring the total length to 227 kilometers. Meanwhile, there will be seven rail transit lines totaling 206.48 kilometers in Guangzhou, and seven rail transit lines totaling 263.1 kilometers in Nanjing. With other cities' planning taken into account, the total length of rail transit lines will come to some 2, 200 kilometers in this country.At present, the constraints to the development of rail transit in China mainly lie in three aspects:First, there is severe shortage of construction funds. According to the foregoing planning, it is necessary to invest in approximately RMB300 billion. Projects to be completed by 2006 alone require more than RMB150 billion. Furthermore, in most cases, funds come from investments of the central and local governments as well as bank loans. Still a developing country as it is, China has very limited financial strength.Second, as rail transit is demanding on technical standard, some key technical facilities at low ratio of home mading at present largely rely on imports. Thus, construction cost remains hig h due to the import of large quantity of technolog y and equipment.Third, in most cases, rail transit operates at a loss in China. That aggregates the centraland local governments' financial burdens, which, in return, checks the development of rail transit to some extent.For this reason, China formulated the guideline of "doing what the strength allows, implementing rules-based management and pursuing stable development". In the development of rail transit, it is required that homemade equipment should take up at least 70 per cent. Meanwhile, it is essential to ensure that development of rail transit suits the pace of economic development in the cities and prevent blind development and irrational attempts to advance forward.Railway Terms and New Wordsurban adj. 城市的, 市内的, urban rail transit（URT）城市轨道交通alleviate vt. 减轻congested adj. 拥挤的，congest vt.，congestion n.accelerate v. 加速, 促进comprehensive adj. 全面的，广泛的cosmopolitan adj. 世界性的，全球（各地）的proportion n. 比例, 均衡, 面积, 部分underground adj. 地下的, 地面下的, 秘密的n. [英] 地铁adv. 秘密地trolley bus n. 电车, (电车)滚轮, 手推车, 手摇车, 台车magnetic adj. 磁的, 有磁性的, 有吸引力的suspension n. 吊, 悬浮, 悬浮液, 暂停, 中止, 悬而未决, 延迟basically adv. 基本上, 主要地unidirectional adj. 单向的, 单向性的the Tenth Five-Year Plan 第十个五年规划at a loss 低于成本的in return 作为报答compete with 与…争夺，competition n.Reading MaterialThe Rising Motorization of ChinaChina’s motorization rate has grown in accordance with other rapidly developing countries, but because of China’s high population, the impacts of motorization are potentially more severe. Figure 1 shows the exponential increase in personal automobile ownership rates. Currently, there are about seven personal automobiles per 1000 people,5compared to over 700 vehicles per 1000 people in industrialized nations like the United States. This figure does not include privately owned trucks or publicly owned vehicles (including buses and trucks), which increases the number of automobiles to about 28 vehicles per 1000 people. If China were to achieve motorization rates comparable to those of developed countries, the environmental and economic consequences could be disastrous. By 2020, the total automobile fleet (not including motorcycles) is expected to grow by between three and seven times the current size depending on economic growth rates (NRC 2003).The population distribution of China is diverse, with the majority of the population (60%) living in rural areas. However, in the past several decades, the improved economic situation of the cities has caused a rapid urban in-migration. This trend has resulted in a nearly three-fold increase in urban development and density in the last decade as displayed in Figure 2. Much of this development is not necessarily representative of sustainable transit and pedestrian oriented growth. Although this new development is very dense, low land cost at the periphery cause developers to build spatially separated housing and commercial developments with few transit connections to the urban center (Gaukenheimer 1996).The western provinces are the most sparsely populated with the largest urban population centers located in provinces along the eastern coast, in metropolises such as Shanghai, Beijing, and Guangzhou. These cities have been experiencing high motorization rates partially because of their higher incomes, but non-motorized modes still capture approximately 70% of the work trip commutes in these cities, while the personal automobile only accounts for 7% (Hu 2003). Much of the transportation and planning research has been centered on these cities, although they constitute a rather small portion of the entire population. Figure 3 shows the amount of cities of different sizes and the approximate total population of people living in cities of different size. Two thirds of the urban population resides in cities with populations between 0.5 and 2 million, indicating that much of the planning and transportation research related to China is focusing on problems that might not be relevant or applicable to the majority of the Chinese population. Economically, most of these cities are years or decades behind the more developed Chinese cities and have not developed many of the transportation problems Beijing, Shanghai and Guangzhou have. Focusing planning efforts in these cities could have much greater returns.The Chinese economy has been growing at a phenomenal rate for the past decade and has doubled in size in the last nine years. In fact, the growth rate is so fast that the Chinese government is imposing several measures to try to control growth to keep it at a more sustainable level (Economist 2004). China’s growth has largely been a result of investment in a few “pilla r” industries. The highest growing pillar industries are: electronic manufacturing, automobiles, electric power, and steel. The eighth five-year plan (1991-1995) designated the automobile industry as one of the pillar industries of economic development. This policy statement encourages the growth of an indigenous auto industry that will be able to supply a large portion of its domestic demand and create a strong export market. It calls for the consolidation of over one hundred companies into 3 or 4 largecompetitive companies. The auto industry accounts for 20% of Shanghai’s gross regional product (Hook 2002). However, with China’s entry into the World Trade Organization (WTO) in 2001, they must reduce tariffs on imported automobiles and can no longer protect their market. This has spurred development of the domestic automobile industry to a level that can compete with international competitors. One of the greatest challenges of cities in China is controlling automobile ownership growth, while fostering the national policy of growing the automobile industry.Costs and Benefits of MotorizationThe cost and benefit implications for Chinese motorization are enormous. Motorization is a major economic growth strategy. The government has adopted a strategy of developing an automobile manufacturing industry. Automobiles can also provide indirect economic benefits of decreased travel time, improved accessibility to goods and services, and new found mobility that will cause people to travel more and achieve a more mobile lifestyle that they would not have otherwise been able to experience.The potential costs are enormous. The United States has the highest motorization rate in the world and perhaps the most mature automobile industry. However, the US has also experienced very high costs associated with our level of motorization. The most obvious and potentially most severe cost is the air pollution and greenhouse gas emissions associated with the automobile. The US emits 26% of the global greenhouse gases but only constitutes 5% of the worl d’s population. China’s policy goal is to achieve Euro II emissions standards by 2005 (about a decade behind Europe) and be internationally compliant with Euro IV standards by 2010. This is a very ambitious goal, but it is necessary if Chinese automakers want to compete in the international market and improve the air quality in their own country. With the three to seven-fold growth rate anticipated in the next 15 years, CO2 emissions will likely quadruple, CO, and hydrocarbons will likely triple, and NO x and particulate matter will likely stay the same. This assumes an aggressive emissions regulation strategy and a modest economic growth rate (NRC 2003). The US EPA has identified all of these emissions as having serious health effects at high concentrations. From a global perspective, China’s motorization could have adverse effects on the global climate. Currently, the transportation sector accounts for 17% of the greenhouse emissions, but this proportion could increase significantly if the motorization trends continue. China is also the second highest consumer of oil in the world (behind the United States). If China motorizes as rapidly as expected, the increase demand could cause the global price of fuel to skyrocket.Another major issue associated with increased motorization is changes in land use. As incomes increase, people desire more living space, which reduces density and encourages expansion at the urban fringe. Figure 4 shows the growth of residential floor space per capita, which is a force toward lower density. This requires more auto oriented transportation infrastructure as well as more land for development. In Shanghai, approximately 10% of the land area is devoted to transportation infrastructure (compared to 20-25% in Europe) (Shen 1997). Because of the built environment, most of the new transportation infrastructure is expanding at the periphery, encouraging auto oriented developments. An increasingly open housing market, where people choose where to live is also creating a spatial jobs-housing imbalance that did not previously exist, when industry provided housing for its employees adjacent to their plants. This greatly increases the cost of transportation for Chinese households as indicated by Figure 5. The proportion of a households income spent on transportation has increases ten fold in less than 15 years. Another major consideration is the conservation of agricultural land. China currently has a very low amount of agricultural land per capita (World Bank 2001)and cannot afford to lose more through urban expansion (Franke 1997).Additional costs include accidents and injuries associated with motorization. Currently, the fatality rate (deaths per mile of travel) is 30 times that of the United States, with over 100,000 deaths per year since 2001, many of which are pedestrians and bicyclists (NRC 2003, Hook 2002b). Additionally equity issues must be considered, specifically the dislocation of the poor. Even with the high projected growth rates in automobile ownership, most Chinese will not own vehicles, so alternative modes must be supplied that can serve the increasing spatial separation between origins and destinations. The cost of the required infrastructure will be enormous and the government will likely have to provide more subsidies to the transportation sector, potentially restricting its investment in other sectors.Causes of MotorizationThe primary impetus for the motorization of China has been the rapid growth of the economy. With a rise in the economic growth of a country comes a desire and means to become more motorized. Motorization rates are associated with a country’s gross domestic product (GDP). Countries with low GDP (below $800) generally have a high proportion of trucks and buses in their vehicle fleets. As GDP increases up to about $10,000, the share of personal automobiles increases drastically until a saturation level is reached (NRC 2003). China’s GDP has been increasing by more than 8% annually for over a decade. A large proportion of upper income people can now afford the luxury of the automobile.Kenworthy et. al. (1999) argue that, while GDP plays an important role, there are many other factors that likely influence motorization rates. By comparing cities with similar GDP and very different transportation energy use, they conclude that land use is a primary factor influencing energy use and thus motorization. Additionally demand management schemes can limit the adverse effect of motorization in China. Currently China’s regulatory structure is weak and inconsistent. Some cities have effectively provided competitive transit alternatives and limited outward expansion (Joos 2000). Others have fully embraced the automobile, pushing many other modes to the side.Railway Terms and New Wordsmotorization n.动力化, 摩托化exponential diverse migration metropolis adj.adj.n.n.指数的, 幂数的不同的, 变化多的移民, 移植, 移往, 移动大城市Chicago, the metropolis of the Midwest.skyrocket v.暴涨，猛涨迅速和突然地升高或使升高：fringe n.边缘, 须边, 刘海periphery n.外围fatality n.命运决定的事物, 不幸, 灾祸, 天命dislocation n.混乱, 断层, 脱臼saturation n.饱和(状态), 浸润, 浸透，饱和度in accordance with 与...一致, 依照per capita 按人口平均计算Chapter 2 Rapid TransitA rapid transit, underground, subway, elevated, or metro system is a railway system, generally in an urban area, that generally has high capacity and frequency, with large trains and total or near total grade separation from other traffic.Definitions and NomenclatureThere is no single term in English that all speakers would use for all rapid transit or metro systems. This fact reflects variations not only in national and regional usage, but in what characteristics are considered essential.One definition of a metro system is as follows; an urban, electric mass transit railway system totally independent from other traffic with high service frequency.But those who prefer the American term "subway" or the British "underground" would additionally specify that the tracks and stations must be located below street level so that pedestrians and road users see the street exactly as it would be without the subway; or at least that this must be true for the most important, central parts of the system. On the contrary, those who prefer the American "rapid transit" or the newer term "metro" tend to regard this as a less important characteristic and are pleased to include systems that are completely elevated or at ground level ( at grade) as long as the other criteria are met. A rapid transit system that is generally above street level may be called an "elevated" system (often shortened to el or, in Chicago, "L" ). In some cities the word "subway" applies to the entire system, in others only to those parts that actually are underground; and analogously for "el".Germanic languages usually use names meaning "underground railway" (such as "subway" or "U-Bahn"), while many others use "metro".Train Size and Motive PowerSome urban rail lines are built to the full size of main-line railways; others use smaller tunnels, limiting the size and sometimes the shape of the trains (in the London Underground the informal term tube train is commonly used). Some lines use light rail rolling stock, perhaps surface cars merely routed into a tunnel for all or part of their route. In many cities, such as London and Boston's MB-TA, lines using different types of vehicles are organized into a single unified system.Although the initial lines of what became the London Underground used steam engines, most metro trains, both now and historically, are electric multiple units, with steel wheels running on two steel rails. Power is usually supplied by means of a single live third rail (as in New York) at 600 to 750 volts, but some systems use two live rails (noticeably London) and thus eliminate the return current from the running rails. Overhead wires, allowinghigher voltages, are more likely to be used on metro systems without much length in tunnel, as in Amsterdam; but they also exist on some that are underground, as in Madrid. Boston's Green Line trains derive power from an overhead wire, both while traveling in a tunnel in the central city and at street level in the suburban areas.Systems usually use DC power instead of AC, even if this requires large rectifiers for the power supply. DC motors were formerly more efficient for railway applications, and once a DC system is in place, converting it to AC is usually considered too large a project to contemplate.TracksMost rapid transit systems use conventional railway tracks, though since tracks in subway tunnels are not exposed to wet weather, they are often fixed to the floor instead of resting on ballast. The rapid transit system in San Diego, California operates tracks on former railroad rights of way that were acquired by the governing entity.Another technology using rubber tires on narrow concrete or steel railways was pioneered on the Paris M6tro, and the first complete system to use it was in Montreal. Additional horizontal wheels are required for guidance, and a conventional track is often provided in case of flat tires and for switching. Advocates of this system note that it is much quieter than conventional steel-wheeled trains, and allows for greater inclines given the increased traction allowed by the rubber tires.Some cities with steep hills incorporate mountain railway technologies into their metros. The Lyon Metro includes a section of rack (cog) railway, while the Carmelit in Haifa is an underground funicular.For elevated lines, still another alternative is the monorail. Supported or "straddle" monorails, with a single rail below the train, include the Tokyo Monorail; the Schwebebahn in Wuppertal is a suspended monorail, where the train body hangs below the wheels and rail. Monorails have never gained wide acceptance except for Japan, although Seattle has a short one, which it hopes to replace with a new, larger system, and one has lately been built in Las Vegas. One of the first monorail systems in the United States was installed at Anaheim's Disneyland in 1959 and connects the amusement park to a nearby hotel. Disneyland's builder, animator and filmmaker Walt Disney, offered to build a similar system between Anaheim and Los Angeles.Crew Size and AutomationEarly underground trains often carried an attendant on each car to operate the doors or gales, in addition to a driver. The introduction of powered doors around 1920 permitted crew sizes to be decreased, and trains in many cities are now operated by a single person. Where the operator would not be able to see the whole side of the train to tell whether thedoors can be safely closed, mirrors or closed-circuit TV monitors are often provided for that purpose.An alternative to human drivers became available in the 1960s, as automated systems were developed that could start a train, accelerate to the correct speed, and stop automatically at the next station, also taking into account the information that a human driver would obtain from lineside or cab signals. The first complete line to use this technology was London's Victoria Line, in 1968. In usual operation the one crew member sits in the driver's position at the front, but just closes the doors at each station; the train then starts automatically. This style of system has become widespread. A variant is seen on London's Docklands Light Railway, opened in 1987, where the "passenger service agent" (formerly "train captain") rides with the passengers instead of sitting at the front as a driver would. The same technology would have allowed trains to operate completely automatically with no crew, just as most elevators do; and as the cost of automation has decreased, this has become financially attractive. But a countervailing argument is that of possible emergency situations. A crew member on board the train may be able to prevent the emergency in the first place, drive a partly failed train to the next station, assist with an evacuation if needed, or call for the correct emergency services (police, fire, or ambulance) and help direct them.In some cities the same reasons are considered to justify a crew of two instead of one; one person drives from the front of the train, while the other operates the doors from a position farther back, and is more conveniently able to help passengers in the rear cars. The crew members may exchange roles on the reverse trip ( as in Toronto) or not (as in New York ) .Completely crewless trains are more accepted on newer systems where there are no existing crews to be removed, and especially on light rail lines. Thus the first such system was the VAL (automated light vehicle) of Lille, France, inaugurated in 1983. Additional VAL lines have been built in other cities. In Canada, the Vancouver Sky Train carries no crew members, while Toronto's Scarborough RT, opening the same year (1985) with otherwise similar trains, uses human operators.These systems generally use platform-edge doors (PEDs) , in order to improve safety and ensure passenger confidence, but this is not universal; for example, the Vancouver SkyTrain does not ( And on the contrary, some lines which retain drivers, however, still use PEDs, noticeably London' s Jubilee Line Extension. MTR of Hong Kong also uses platform screen doors, the first to install PSDs on an already operating system. ) With regard to larger trains, the Paris Metro has human drivers on most lines, but runs crewless trains on its newest line, Line 14, which opened in 1998. Singapore's North EastMRT Line (2003) claims to be the world' s first completely automated underground urban heavy rail line. The Disneyland Resort Line of Hong Kong MTR is also automated.Tunnel ConstructionThe construction of an underground metro is an expensive project, often carried out over many years. There are several different methods of building underground lines.In one usual method, known as cut-and-cover, the city streets are excavated and a tunnel structure strong enough to support the road above is built at the trench, which is then filled in and the roadway rebuilt. This method often involves extensive relocation of the utilities usually buried not for below city streets—especially power and telephone wiring, water and gas mains, and sewers. The structures are generally made of concrete, perhaps with structural columns of steel; in the oldest systems, brick and cast iron were used. Cut-and-cover construction can take so long that it is often necessary to build a temporary roadbed while construction is going on underneath in order to avoid closing main streets for long periods of time; in Toronto, a temporary surface on Yonge Street supported cars and streetcar tracks for several years while the Yonge subway was built.Some American cities, like Newark, Cincinnati and Rochester, were originally built around canals. When the railways took the place of canals, they were able to bury a subway in the disused canal's trench, without rerouting other utilities, or acquiring a right of way piecemeal.Another common way is to start with a vertical shaft and then dig the tunnels horizontally from there, often with a tunneling shield, thus avoiding almost any disturbance to existing streets, buildings, and utilities. But problems with ground water are more likely, and tunneling through native bedrock may require blasting. (The first city to extensively use deep tunneling was London, where a thick sedimentary layer of clay largely avoids both problems. ) The confined space in the tunnel also restricts the machinery that can be used, but specialised tunnel-boring machines are now available to overcome this challenge. One disadvantage with this, nevertheless, is that the cost of tunneling is much higher than building systems cut-and-cover, at-grade or elevated. Early tunnelling machines could not make tunnels large enough for conventional railway equipment, necessitating special low round trains, such as are still used by most of the London Underground, which cannot fix air conditioning on most of its lines because the amount of empty space between the trains and tunnel walls is so small.The deepest metro system in the world was built in St. Petersburg, Russia. In this city, built ii the marshland, stable soil starts more than 50 meter deep. Above that level the soil is mostly made up of water-bearing finely dispersed sand. As a result of this, only three stations out of nearly 60 are built near the ground level and three more above the ground.。
交通运输专业英语 (6)
（3）Some lawbreakers make use of the leaks of the car rental contract to entice away the car. Thus, the car rental company has to pay their own money in exchange of the cars according to a deputy to the National People's Congress in 2010.
The health of the car rental industry partially determines whether the whole car industry can maximize its profits.
China’s car rental industry still faces many problems that need to be dealt with in order to let it develop healthily.
Lesson 1 Car Leasing
1.3 Lacking of Enough Publicity and Advertising
In fact, the authors themselves have to admit that it is hard to find some advertisements about the car rental companies.