【正文】 f 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 carpooled, and 6 million used public transportation.The technologies and the resulting modes available today for urban transportation are mon 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 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。本科畢業(yè)設(shè)計(jì)（論文）外文翻譯專業(yè)名稱：土木工程年級(jí)班級(jí)：學(xué)生姓名：指導(dǎo)教師：河南理工大學(xué)土木工程學(xué)院二○ 年 月 日河南理工大學(xué)本科畢業(yè)設(shè)計(jì)（論文） 外文翻譯Urban transportation Planning An urban transportation system is basic ponent of an urban area39。 Michael D. Meyer and Eric J. Miller Urban Transportation Planning, 1984城市交通規(guī)劃城市交通系統(tǒng)是市區(qū)的社會(huì)、經(jīng)濟(jì)、和物質(zhì)結(jié)構(gòu)的一個(gè)基本組成部分。離開家的出行者可以乘坐當(dāng)?shù)氐墓财嚩竭_(dá)另一個(gè)郊區(qū)地鐵車站（出行集合過程），經(jīng)車站轉(zhuǎn)到地鐵站臺(tái)（換乘過程），乘地鐵到達(dá)一個(gè)商業(yè)車站（沿線運(yùn)行過程），然后步行到工作地點(diǎn)（分散過程）。從歷史上看,城市交通系統(tǒng)曾經(jīng)是一個(gè)決定城市形態(tài)的重要因素。支撐的類型引導(dǎo)的手段，以及控制技術(shù)。 然而，由于內(nèi)燃機(jī)技術(shù)提供了比有軌交通方式更為廉價(jià)的和更為靈活的汽車，從而導(dǎo)致了市區(qū)內(nèi)其他交通方式的衰落。traffic actuated39。 控制車輛，騎自行車的人和行人的信號(hào)是在特定時(shí)間間隔分配到各種交通活動(dòng)的預(yù)定時(shí)間和在交通運(yùn)轉(zhuǎn)中控制全部或部分交通需求的的時(shí)間間隔。然而對(duì)于短循環(huán)，清理路口和開始每一次順利的運(yùn)轉(zhuǎn)消耗的時(shí)間相對(duì)較高。在許多路口，信號(hào)必須被定好來調(diào)整行人流動(dòng)。如果行人命令按鈕被合并到整體的控制系統(tǒng)，一個(gè)單獨(dú)的行人信號(hào)必須放在這個(gè)街道中間。交互式系統(tǒng)在相同的時(shí)間有所有的信號(hào)轉(zhuǎn)換。這允許在設(shè)計(jì)速度中的至少一個(gè)方向的一組車輛速度連續(xù)或接近連續(xù)流動(dòng)，并阻礙了信號(hào)之間的超速駕駛。交通感應(yīng)系統(tǒng)是一種具有調(diào)整交通信號(hào)設(shè)置來測(cè)量交通量的能力的先進(jìn)彈性連續(xù)性系統(tǒng)。 at 10 mph （16km/h) the flow rate is only 1000。 little or no restrictions on maneuverability from other vehicles.Level C—Stable flow。一個(gè)現(xiàn)代公路通行能力的的抽樣情況如下： 設(shè)施小客車通行能力遠(yuǎn)離斜坡和交織路段的高速公路和每小時(shí)每個(gè)車道的車流量2000兩車道公路，每小時(shí)兩個(gè)方向的車流量2000三車道公路，每小時(shí)一個(gè)方向的車流量2000有信號(hào)的交叉路口的十二英寸車道，在綠燈條件下每小時(shí)的車流量（沒有干擾的理想通行條件下）1800 關(guān)于通行能力處理量，運(yùn)輸交通委員會(huì)發(fā)布的公路通行能力手冊(cè)將高速公路劃分為以下部分：基本高速公路路段，這些區(qū)域有影響的交織地區(qū)和砸道連接處，高速公路，多車道公路。（48到64km/h）的速度下穩(wěn)定在大約2000車輛每小時(shí)。這樣的沖擊波已經(jīng)在視野里從原來的擁擠點(diǎn)達(dá)到幾英里。實(shí)地觀察記錄車輛的間隔時(shí)間（車與車之間的時(shí)間）。對(duì)于達(dá)到車輛不間斷流動(dòng)的服務(wù)水平的最好措施是行駛速度，到達(dá)最大限度時(shí)的播報(bào)，v/c率。運(yùn)輸研究委員會(huì)手冊(cè)說明的另一種表明服務(wù)水平的方法是交通密度。比如，如果平均速度是50英里每小時(shí)，車輛在在一確定的一英里車道上是72s。對(duì)于各種服務(wù)水平的運(yùn)行條件的簡(jiǎn)單說明如下：A級(jí)—車輛流通順暢，車速受司機(jī)控制，速度受到限制，或者適應(yīng)實(shí)際道路條件。但是，即使在最好的交通條件下，車流中的差距也是可能會(huì)出現(xiàn)的，所以如此高的車流是不常見的。速度限制在60、。在這種情況下，車流量迅速下降，這種情況下的交通受益被稱為“強(qiáng)制性流動(dòng)”?；靖咚俟泛投嘬嚨拦仿范嗡俣?，車流量和通行能力的關(guān)系 速度，車流量和通行能力之間關(guān)系是了解某一地方公路設(shè)計(jì)和運(yùn)行能力的基礎(chǔ)。 tolerable speeds can be maintained but temporary restrictions to flow cause substantial drops in speed. Little freedom to maneuver，fort and convenience low.Level E—Volumes near capacity。s feeling of freedom or constraint more than any other factor. Studies of drivers as they follow other vehicles indicate that the time required to reach a potential collision point，rather than vehicle separation，seems to control behavior. However，this time varies widely among drivers and situations. Field observations have recorded headways (time between vehicles) ranging from 0. 5 to 2 sec, with an average of about 1. ，the calculated capacity of a traffic lane based on this 1. 5 s average, regardless of speed，will be 2400 vehicles per hour. But even under the best of conditions, occasional gaps in the traffic stream can be expected，so that such high flows are not mon. Rather, as noted，they are nearer to 2000 passenger cars per hour.The ‘Level of Service’ Concept As indicated in the discussion of the relationships of speed, volume or density, and vehicle spacing, operating speed goes down and driver restrictions bee greater as traffic volume increase. ‘Level of service’ is monly accepted as a measure of the restrictive effects of increased volume. Each segment of roadway can be rated at an appropriate level，A to F inclusive，to reflect its condition at the given demand or service volume. Level A represents almost ideal conditions。對(duì)于它們，探測(cè)器僅被布置在次要街道。彈性連續(xù)前進(jìn)信號(hào)系統(tǒng)有一種主控制器裝置來指導(dǎo)個(gè)別信號(hào)控制器。交互式系統(tǒng)在大約相等的街區(qū)間隔的信號(hào)街上能相當(dāng)好的工作。在正常的交通量下，適當(dāng)?shù)恼{(diào)整從2500英尺（）到超過一英里（）的各種信號(hào)間隔對(duì)于形成流暢的交通是非常有效的。對(duì)于單獨(dú)的行人指示，步行指示（淺白色）包括最開始的時(shí)間間隔，禁止通行閃光燈（橘黃色）包括了剩余的時(shí)間間隔。對(duì)于高流量的交通，可能需要增加循環(huán)周期來獲得更大的通行能力。它們有這些優(yōu)勢(shì)，包括有低生產(chǎn)成本的控制器，可以聯(lián)系和協(xié)調(diào)使車輛以最少的?？亢推渌难舆t通過一系列的交叉口。Pretimed39。于此同時(shí)，特別是自第二次世界大戰(zhàn)結(jié)束以來，私人汽車使用的增長(zhǎng)，一般來說已顯著的使公共交通的使用縮減。有軌電車的出現(xiàn)使城市地區(qū)超出了之前運(yùn)輸技術(shù)（例如走路、騎馬、馬車）所限定的界限進(jìn)行了擴(kuò)展。這個(gè)關(guān)系還暗示可供與交通問題打交道的政府官員多采用的選擇方案。當(dāng)提供這些出行機(jī)會(huì)的公共設(shè)施和服務(wù)集合起來,使從一個(gè)地點(diǎn)到另一個(gè)地點(diǎn)的運(yùn)動(dòng)成為可能時(shí)就會(huì)形成網(wǎng)絡(luò)。這樣，為了發(fā)展和維護(hù)城市交通系統(tǒng)而制定的規(guī)劃是一項(xiàng)重要的活動(dòng)，既是為了促進(jìn)人和貨物在市區(qū)的有效運(yùn)轉(zhuǎn)，同時(shí)也是為了保持交通在實(shí)現(xiàn)其他社團(tuán)目標(biāo)方而所能起到的強(qiáng)有力的支援作用。 the transportation technologies that provide the means of moving over these distances。 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 available 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 considerations 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 location 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