外文翻譯--交通事故分析的可能性和局限性

1、外文翻譯-交通事故分析的可能性和局限性 外 文 翻 譯題 目： 交通事故分析的可能性和局限性 交通事故分析的可能性和局限性關(guān)鍵字：后果;目的;描述;限制;關(guān)注;事故分析;可能性摘要：交通事故的統(tǒng)計(jì)數(shù)字，尤其國家一級的數(shù)據(jù)對監(jiān)控和預(yù)測事故的開展，積極或消極檢測事故的開展，以及對定義平安目標(biāo)和評估工業(yè)平安特別有益。事故分析是應(yīng)用非常有限的分析，是前瞻性分析和回憶性分析，能夠?qū)π麻_發(fā)的交通平安系統(tǒng)和特殊過程的平安措施進(jìn)行評價。目前迫切需要一個將實(shí)時事故分析與研究相結(jié)合的行為。將自動檢測和視頻錄制相結(jié)合的研究交通事故的科研論文會比擬容易接受。這種類型的研究最終會對交通理念有個完善的認(rèn)識。1簡介本文主要

2、是基于個人的經(jīng)驗(yàn)，研究有關(guān)交通平安、平安分析以及事故分析等在研究中的作用。由這些經(jīng)驗(yàn)推導(dǎo)出的哲學(xué)思考就像通過研究和統(tǒng)計(jì)得出的實(shí)踐觀點(diǎn)。而這些調(diào)查數(shù)字已經(jīng)在其他地方發(fā)表了。在缺少直接觀察事故，。事實(shí)證明，用來解釋事故的大局部有關(guān)信息事故中的記錄。深入研究還無法回憶起所有的必要的測試有關(guān)事故發(fā)生的假設(shè)數(shù)據(jù)，。發(fā)生車禍，這是荷蘭城市道路交叉口，汽車相撞，以下問題可以問：為什么汽車，突然加速后幾乎停止，在左側(cè)主路呢？為什么沒有注意到來的車？兩從右邊，為提供可能性？難道他，但他認(rèn)為？當(dāng)然，交通并不復(fù)雜。目前事故沒有騎自行車或行人在擁擠路口分散他的注意。，。新的視頻設(shè)備和自動檢測事故的開展，如數(shù)據(jù)變得越來

3、越逼真數(shù)據(jù)類型關(guān)于事故的可能性和限制的問題答復(fù)我們不能事故。事故分析涵蓋了的背景，并根據(jù)不同的信息來源范圍補(bǔ)充資料，特別是收集事故數(shù)據(jù)，背景資料等我們首先要看看在交通平安領(lǐng)域的活動周期答復(fù)的可能性與限制。這些主要交通系統(tǒng)的平安管理，有些那么是研究活動。研究人員研究事故發(fā)生時一連串事件中每個人的興趣。希望從中得到關(guān)于每次事故的詳細(xì)信息并能發(fā)現(xiàn)其發(fā)生的原因和有關(guān)的條件。政治家們希望只是因?yàn)榧?xì)節(jié)決定行動。在最高一級事故總數(shù)減少。信息的主要來源是國家數(shù)據(jù)庫及其統(tǒng)計(jì)學(xué)處理系統(tǒng)。對他來說，統(tǒng)計(jì)意外數(shù)字及其統(tǒng)計(jì)的波動來進(jìn)行事故分析。這適用于事故分析中的交通平安領(lǐng)域。因此，我們將首先描述了事故的這些方面。2事

4、故的性質(zhì)和它們的統(tǒng)計(jì)特性事故根本概念是意外，不管是其發(fā)生的原因還是引起事故出現(xiàn)的過程。兩個簡單的假設(shè)通常是來描述交通事故的形成過程：-事故發(fā)生的概率與以往發(fā)生的事故之間是獨(dú)立；-事故發(fā)生在時間上是同性質(zhì)的如果這兩個假設(shè)成立，那么事故是泊松分布。第一個假設(shè)與大多數(shù)的批判不符。事故是罕見的事件，因此不會受到以前事故的影響。在某些情況下，有一個直接的因果鏈例如，大量的車開到一起這一系列的事故被認(rèn)為是一個個體事故但包含許多的車。這個假設(shè)并不適用于統(tǒng)計(jì)人員傷亡。傷亡人數(shù)往往與同一事故有關(guān)，因此，獨(dú)立性假設(shè)不成立。第二個假設(shè)乍一看似乎不太容易理解。穿越空間或在不同地點(diǎn)發(fā)生的的事故同樣具有可能性。然而，假設(shè)

5、需要很長一段時間并且沒有緩繳期。其性質(zhì)是根據(jù)理論的假設(shè)。如果其短時間內(nèi)能成立，那么它也適用于長時間，因?yàn)椴此煞植甲兞康目偤?，即使他們的泊松率是不同的，但也屬于泊松分布。對于這些時期的總和泊松率那么等于為這些地方的泊松率的總和。假設(shè)與一個真正的情況相比擬計(jì)數(shù)，無論是從一兩個結(jié)果還是總情況來看都有一個根本情況比擬符合。例如，。如果條件是相同的同一時間，交通，同樣的天氣條件等，那么由此產(chǎn)生的意外數(shù)字是相同的泊松過程的結(jié)果。這一假設(shè)可以通過估算進(jìn)行測試的兩個觀測值的根底上估計(jì)是兩個值的平均值的速度參數(shù)。概率理論考慮到兩個觀察用于計(jì)算的平等假設(shè)的可能性。這是一相當(dāng)強(qiáng)大統(tǒng)計(jì)過程。泊松假設(shè)是研究了很屢次，證

6、據(jù)支持。它已經(jīng)應(yīng)用許多情況，數(shù)差異說明在平安的差異確定是否發(fā)生意外。這一程序的主要目的是檢測在平安分歧。這可能是一個時間上的差異，或不同的地方或不同的條件。這種差異可以指導(dǎo)改良的過程。由于主要關(guān)注的是，以減少意外的發(fā)生，這種分析可能導(dǎo)致對治療中最有前途的領(lǐng)域。為這樣一個測試應(yīng)用程序的必要條件是，那意外的數(shù)字進(jìn)行比擬是大到足以證明存在的分歧。在許多地方情況下，一個應(yīng)用程序是不可能的。事故黑點(diǎn)分析往往阻礙了這一限制，例如，如果應(yīng)用這種測試，找出事故是否在特定的位置數(shù)是高于平均水平。該程序的描述，也可以使用，如果發(fā)生意外乃根據(jù)數(shù)的特點(diǎn)找到有前途的平安目標(biāo)。不僅聚集，而且還與分類泊松假設(shè)成立，意外數(shù)字

7、可以相互測試的泊松假設(shè)的根底。這種測試是相當(dāng)麻煩的，因?yàn)槊總€特定的情況下，每一個不同的泊松參數(shù)，即，對所有可能結(jié)果的概率必須計(jì)算應(yīng)用測試。然后，泊松分布近似為正態(tài)分布，均值和方差等于泊松參數(shù)。一旦均值和方差的正態(tài)分布，給出了所有的測試可以改寫了標(biāo)準(zhǔn)零均值和方差的正態(tài)分布條件。沒有任何更多的必要計(jì)算，但測試統(tǒng)計(jì)，表繪制。1、該測試應(yīng)用推廣到高階分類。Foldvary和Lane1974，在衡量強(qiáng)制佩戴平安帶的效果，誰是最早應(yīng)用于值的4路表高階相互作用的總卡方分配的。 2、測試不局限于總體影響，但卡方值就可以分解模型內(nèi)子假說。另外，在雙向表，卡方總可以分解成零件表互動的作用。對1的優(yōu)勢。和2。比以前

8、的情況是，這對許多相互關(guān)聯(lián)的子表和相應(yīng)的智廣場卡方檢驗(yàn)是由大量分析，取而代之的是一個一卡方確實(shí)切劃分。 3、投入更多關(guān)注的是參數(shù)估計(jì)。例如，在卡方分割使人們有可能以測試有關(guān)行參數(shù)的線性或二次限制或趨勢的不連續(xù)性。4、分析的單位是從數(shù)到廣義加權(quán)計(jì)數(shù)。這對于道路平安分析，那里一段時間，道路使用者的數(shù)量，地點(diǎn)或公里數(shù)的車輛往往是必要的修正有利。最后一個選項(xiàng)是沒有發(fā)現(xiàn)在許多統(tǒng)計(jì)軟件包。安徒生1977年給出了一個用于道路雙向平安分析表的例子。工資保障運(yùn)動的一個計(jì)算機(jī)程序。這一級沒有說明事故原因分析。它會嘗試檢測平安問題需要特別注意。所需的根本信息包括事故數(shù)字，來形容不平安總額，暴露的數(shù)據(jù)來計(jì)算風(fēng)險，并找

9、到一個高風(fēng)險的情況下或團(tuán)體道路使用者。 交通平安的研究是有關(guān)的事故及其后果的發(fā)生。因此，人們可能會說，研究對象是意外。然而研究人員的興趣較少集中在這個最后的結(jié)果本身，而是多在進(jìn)程更多的結(jié)果或不結(jié)果的事故。因此，最好是把作為他的研究對象，在流量的重要事件。一個在交通意外的過程，結(jié)果是，該實(shí)際發(fā)生是由研究者未落觀測研究的主要問題。調(diào)查一宗交通意外，他將努力重建了間接來源的事件，如涉及的道路使用者，所提供的資料或目擊者有關(guān)情況，車輛，道路和司機(jī)的特點(diǎn)。因此這不是科學(xué)獨(dú)特的，也有一個間接的研究對象的研究更多的例子。但是，第二個困難是，該研究的對象不能被誘發(fā)。有系統(tǒng)的控制實(shí)驗(yàn)手段研究只對問題方面的可能，

10、而不是問題本身。間接觀察和缺乏系統(tǒng)的控制組合使調(diào)查人員很難發(fā)現(xiàn)在什么情況下造成事故的因素。雖然研究人員主要是在事故處理領(lǐng)導(dǎo)有興趣，他幾乎完全信息的后果，它的產(chǎn)品，意外。此外，事故背景是復(fù)雜的。一般來說，可分為以下幾個方面： -考慮到交通系統(tǒng)，交通量和組成國家，道路使用者，他們的速度，天氣條件下，路面情況，車輛，道路使用者和他們的相互作用的演習(xí)，意外可以或無法預(yù)防。 -由于發(fā)生事故，也對這樣的速度和車輛質(zhì)量的因素，大量的不同，碰撞角度，對道路使用者和他們的脆弱性，影響等位置的保護(hù)，傷害是嚴(yán)重或或多或少物質(zhì)損失是多還是少可觀。雖然這些方面不能獨(dú)立研究從理論的角度看，它也從由此產(chǎn)生的結(jié)果的優(yōu)勢，區(qū)分

11、交通情況有潛在危險的數(shù)字，是由有一個意外的可能性，在這種潛在的危險局勢，給定一個特定事故。這個概念框架是對風(fēng)險的關(guān)于個別道路使用者，以及上級的決定控制器的決定制定的一般根底。在風(fēng)險的數(shù)學(xué)公式，我們需要一個明確的概率空間的介紹，根本領(lǐng)件的情況，可能導(dǎo)致事故組成，每個類型的事件的概率，最終收在一次事故中，最后的具體成果，損失，鑒于事故的類型。另一種方法是看事故特征組合，找出關(guān)鍵因素。這種類型的分析。事故本身，道路道路位置，道路設(shè)計(jì)如一個等SWOV institute for road safety research Leidschendam會議記錄S.Oppe.POSSIBILITIES AND

12、LIMITATIONS OF ACCIDENT ANALYSISKeyword：Consequences; purposes; describe; Limitations; concerned; Accident Analysis; possibilitiesAbstraet：Accident statistics, especially collected at a national level are particularly useful for the description, monitoring and prognosis of accident developments, the

13、 detection of positive and negative safety developments, the definition of safety targets and the product evaluation of long term and large scale safety measures. The application of accident analysis is strongly limited for problem analysis, prospective and retrospective safety analysis on newly dev

14、eloped traffic systems or safety measures, as well as for process evaluation of special short term and small scale safety measures. There is an urgent need for the analysis of accidents in real time, in combination with background behavioural research. Automatic incident detection, combined with vid

15、eo recording of accidents may soon result in financially acceptable research. This type of research may eventually lead to a better understanding of the concept of risk in traffic and to well-established theories.1. Introduction.This paper is primarily based on personal experience concerning traffic

16、 safety, safety research and the role of accidents analysis in this research. These experiences resulted in rather philosophical opinions as well as more practical viewpoints on research methodology and statistical analysis. A number of these findings are published already elsewhere.From this lack o

17、f direct observation of accidents, a number of methodological problems arise, leading to continuous discussions about the interpretation of findings that cannot be tested directly. For a fruitful discussion of these methodological problems it is very informative to look at a real accident on video.

18、It then turns out that most of the relevant information used to explain the accident will be missing in the accident record. In-depth studies also cannot recollect all the data that is necessary in order to test hypotheses about the occurrence of the accident.For a particular car-car accident, that

19、was recorded on video at an urban intersection in the Netherlands, between a car coming from a minor road, colliding with a car on the major road, the following questions could be asked:Why did the driver of the car coming from the minor road, suddenly accelerate after coming almost to a stop and hi

20、t the side of the car from the left at the main road? Why was the approaching car not noticed? Was it because the driver was preoccupied with the two cars coming from the right and the gap before them that offered him the possibility to cross? Did he look left before, but was his view possibly block

21、ed by the green van parked at the corner? Certainly the traffic situation was not complicated. At the moment of the accident there were no bicyclists or pedestrians present to distract his attention at the regularly overcrowded intersection. The parked green van disappeared within five minutes, the

22、two other cars that may have been important left without a trace. It is hardly possible to observe traffic behaviour under the most relevant condition of an accident occurring, because accidents are very rare events, given the large number of trips. Given the new video equipment and the recent devel

23、opments in automatic incident and accident detection, it becomes more and more realistic to collect such data at not too high costs. Additional to this type of data that is most essential for a good understanding of the risk increasing factors in traffic, it also important to look at normal traffic

24、behaviour as a reference base. The question about the possibilities and limitations of accident analysis is not lightly answered. We cannot speak unambiguously about accident analysis. Accident analysis covers a whole range of activities, each originating from a different background and based on dif

25、ferent sources of information: national data banks, additional information from other sources, specially collected accident data, behavioural background data etc. To answer the question about the possibilities and limitations, we first have to look at the cycle of activities in the area of traffic s

26、afety. Some of these activities are mainly concerned with the safety management of the traffic system, some others are primarily research activities.The following steps should be distinguished:- detection of new or remaining safety problems;- description of the problem and its main characteristics;-

27、 the analysis of the problem, its causes and suggestions for improvement;- selection and implementation of safety measures;- evaluation of measures taken.Although this cycle can be carried out by the same person or group of persons, the problem has a different political/managerial or scientific back

28、ground at each stage. We will describe the phases in which accident analysis is used. It is important to make this distinction. Many fruitless discussions about the method of analysis result from ignoring this distinction. Politicians, or road managers are not primarily interested in individual acci

29、dents. From their perspective accidents are often treated equally, because the total outcome is much more important than the whole chain of events leading to each individual accident. Therefore, each accident counts as one and they add up all together to a final safety result.Researchers are much mo

30、re interested in the chain of events leading to an individual accident. They want to get detailed information about each accident, to detect its causes and the relevant conditions. The politician wants only those details that direct his actions. At the highest level this is the decrease in the total

31、 number of accidents. The main source of information is the national database and its statistical treatment. For him, accident analysis is looking at subgroups of accident numbers and their statistical fluctuations. This is the main stream of accident analysis as applied in the area of traffic safet

32、y. Therefore, we will first describe these aspects of accidents.2. The nature of accidents and their statistical characteristics.The basic notion is that accidents, whatever there cause, appear according to a chance process. Two simple assumptions are usually made to describe this process for traffi

33、c accidents: - the probability of an accident to occur is independent from the occurrence of previousaccidents;-the occurrence of accidents is homogeneous in time.If these two assumptions hold, then accidents are Poisson distributed. The first assumption does not meet much criticism. Accidents are r

34、are events and therefore not easily influenced by previous accidents. In some cases where there is a direct causal chain e.g. , when a number of cars run into each other the series of accidents may be regarded as one complicated accident with many cars involved.The assumption does not apply to casua

35、lties. Casualties are often related to the same accident and therefore the independency assumption does not hold. The second assumption seems less obvious at first sight. The occurrence of accidents through time or on different locations are not equally likely. However, the assumption need not hold

36、over long time periods. It is a rather theoretical assumption in its nature. If it holds for short periods of time, then it also holds for long periods, because the sum of Poisson distributed variables, even if their Poisson rates are different, is also Poisson distributed. The Poisson rate for the

37、sum of these periods is then equal to the sum of the Poisson rates for these parts.The assumption that really counts for a comparison of composite situations, is whether two outcomes from an aggregation of situations in time and/or space, have a comparable mix of basic situations. E.g. , the compari

38、son of the number of accidents on one particular day of the year, as compared to another day the next day, or the same day of the next week etc. . If the conditions are assumed to be the same same duration, same mix of traffic and situations, same weather conditions etc. then the resulting numbers o

39、f accidents are the outcomes of the same Poisson process. This assumption can be tested by estimating the rate parameter on the basis of the two observed values the estimate being the average of the two values . Probability theory can be used to compute the likelihood of the equality assumption, giv

40、en the two observations and their mean. This statistical procedure is rather powerful. The Poisson assumption is investigated many times and turns out to be supported by a vast body of empirical evidence. It has been applied in numerous situations to find out whether differences in observed numbers

41、of accidents suggest real differences in safety. The main purpose of this procedure is to detect differences in safety. This may be a difference over time, or between different places or between different conditions. Such differences may guide the process of improvement. Because the main concern is

42、to reduce the number of accidents, such an analysis may lead to the most promising areas for treatment. A necessary condition for the application of such a test is, that the numbers of accidents to be compared are large enough to show existing differences. In many local cases an application is not p

43、ossible. Accident black-spot analysis is often hindered by this limitation, e.g., if such a test is applied to find out whether the number of accidents at a particular location is higher than average. The procedure described can also be used if the accidents are classified according to a number of c

44、haracteristics to find promising safety targets. Not only with aggregation, but also with disaggregation the Poisson assumption holds, and the accident numbers can be tested against each other on the basis of the Poisson assumptions. Such a test is rather cumbersome, because for each particular case

45、, i.e. for each different Poisson parameter, the probabilities for all possible outcomes must be computed to apply the test. In practice, this is not necessary when the numbers are large. Then the Poisson distribution can be approximated by a Normal distribution, with mean and variance equal to the

46、Poisson parameter. Once the mean value and the variance of a Normal distribution are given, all tests can be rephrased in terms of the standard Normal distribution with zero mean and variance one. No computations are necessary any more, but test statistics can be drawn from tables.3. The use of acci

47、dent statistics for traffic safety policy.The testing procedure described has its merits for those types of analysis that are based on the assumptions mentioned. The best example of such an application is the monitoring of safety for a country or region over a year, using the total number of acciden

48、ts eventually of a particular type, such as fatal accidents , in order to compare this number with the outcome of the year before. If sequences of accidents are given over several years, then trends in the developments can be detected and accident numbers predicted for following years. Once such a t

49、rend is established, then the value for the next year or years can be predicted, together with its error bounds. Deviations from a given trend can also be tested afterwards, and new actions planned. The most famous one is carried out by Smeed 1949. We will discuss this type of accident analysis in m

50、ore detail later.1. The application of the Chi-square test for interaction is generalised to higher order classifications. Foldvary and Lane 1974 , in measuring the effect of compulsory wearing of seat belts, were among the first who applied the partitioning of the total Chi-square in values for the

51、 higher order interactions of four-way tables. 2. Tests are not restricted to overall effects, but Chi-square values can be decomposed regarding sub-hypotheses within the model. Also in the two-way table, the total Chisquare can be decomposed into interaction effects of part tables. The advantage of

52、 1. and 2. over previous situations is, that large numbers of Chi-square tests on many interrelated sub tables and corresponding Chi-squares were replaced by one analysis with an exact portioning of one Chi-square.3. More attention is put to parameter estimation. E.g., the partitioning of the Chi-sq

53、uare made it possible to test for linear or quadratic restraints on the row-parameters or for discontinuities in trends.4. The unit of analysis is generalised from counts to weighted counts. This is especially advantageous for road safety analyses, where corrections for period of time, number of roa

54、d users, number of locations or number of vehicle kilometres is often necessary. The last option is not found in many statistical packages. Andersen 1977 gives an example for road safety analysis in a two-way table. A computer programme WPM, developed for this type of analysis of multi-way tables, i

55、s available at SWOV see: De Leeuw and Oppe 1976 . The accident analysis at this level is not explanatory. It tries to detect safety problems that need special attention. The basic information needed consists of accident numbers, to describe the total amount of unsafety, and exposure data to calculat

56、e risks and to find situations or groups of road users with a high level of risk.4. Accident analysis for research purposes.Traffic safety research is concerned with the occurrence of accidents and their consequences. Therefore, one might say that the object of research is the accident. The research

57、ers interest however is less focused at this final outcome itself, but much more at the process that results or does not result in accidents. Therefore, it is better to regard the critical event in traffic as his object of study. One of the major problems in the study of the traffic process that res

58、ults in accidents is, that the actual occurrence is hardly ever observed by the researcher.Investigating a traffic accident, he will try to reconstruct the event from indirect sources such as the information given by the road users involved, or by eye-witnesses, about the circumstances, the characte

59、ristics of the vehicles, the road and the drivers. As such this is not unique in science, there are more examples of an indirect study of the object of research. However, a second difficulty is, that the object of research cannot be evoked. Systematic research by means of controlled experiments is only possible for aspects of the problem, not for the problem itself.The combination of indirect observation and lac