1、沈陽農業大學學士學位論文外文翻譯3交通事故分析的可能性和局限性 s.oppe關鍵字：后果;目的;描述;限制;關注;事故分析;可能性摘要：交通事故的統計數字，尤其國家一級的數據對監控和預測事故的發展，積極或消極檢測事故的發展，以及對定義安全目標和評估工業安全特別有益。事故分析是應用非常有限的分析，是前瞻性分析和回顧性分析，能夠對新開發的交通安全系統和特殊過程的安全措施進行評價。目前迫切需要一個將實時事故分析與研究相結合的行為。將自動檢測和視頻錄制相結合的研究交通事故的科研論文會比較容易接受。這種類型的研究最終會對交通理念有個完善的認識。1簡介本文主要是基于個人的經驗，研究有關交通安全、安全分析以

2、及事故分析等在研究中的作用。由這些經驗推導出的哲學思考就像通過研究和統計得出的實踐觀點。而這些調查數字已經在其他地方發表了。在缺少直接觀察的事故中，許多方法論問題的產生，導致不能直接測試對結果持續討論。通過看事故視頻來討論是富有成效的。事實證明，用來解釋事故的大部分有關信息就是事故中缺少的記錄。深入研究還無法回憶起所有的必要的用來測試有關事故發生的假設數據，。尤其是車-車相撞發生的車禍，這是在荷蘭城市道路交叉口錄制的視頻，一輛從岔路駛來的汽車與主干路的汽車相撞，下列問題可以問：為什么汽車來自次干路上，突然加速后又幾乎停止，撞上了在左側主路的一輛汽車呢？為什么沒有注意到正在駛來的車？是不是因為兩

3、車從右邊駛來，司機因為前面的交叉為他們提供了可能性而斤斤計較？難道他向左看過，但他認為停在拐角處的綠色貨車能讓他停下來？當然，交通狀況并不復雜。目前這個事故中沒有騎自行車或行人在擁擠路口分散他的注意。如果停著的綠色車能夠在五分鐘內消失，這兩輛車可能就不會相撞。在事故發生的相關條件下，幾乎不可能觀察下一個交通行為，因為交通事故是不可預見的。由于新的視頻設備和自動檢測事故設備的不斷發展，如在收集數據方面不需要很高的成本就能變得越來越逼真。必要的增加數據類型也能更好的解釋交通中存在的危險因素。關于事故分析的可能性和限制性的問題是不容易回答的，我們不能確切的分析交通事故。因為事故分析涵蓋了每一個活動中

4、的不同背景，并根據不同的信息來源范圍來補充資料，特別是收集事故的數據，背景資料等，我們首先要看看在交通安全領域的活動周期然后再回答事故分析的可能性與限制。這些行為主要是與交通系統的安全管理有關，有些則是相關的研究活動。應該用下面的步驟來加以區分：檢測交通安全問題；描述問題和它的主要特征；分析其原因分析和改進建議；選擇和執行安全措施；評價所采取的措施。雖然這個周期可以由同一人或一群人做出來，而問題在每個階段（政治/管理或科學）都有不同的背景。我們用事故分析來描述這一階段。做這個決定是重要的。很多關于分析結果的方法的討論由于忽視之間的區別而成為徒勞的。政治家或道路管理人員對道路的個別事故不是很留意

5、。他們對事故的看法往往都是一視同仁，因為總的結果比整個事故中的每個人的因素重要。因此，每次事故看做一個個體，之間相互協調就會達成安全的結果。研究人員研究事故發生時一連串事件中每個人的興趣。希望從中得到關于每次事故的詳細信息并能發現其發生的原因和有關的條件。政治家們希望只是因為細節決定行動。在最高一級事故總數減少。信息的主要來源是國家數據庫及其統計學處理系統。對他來說，統計意外數字及其統計的波動來進行事故分析。這適用于事故分析中的交通安全領域。因此，我們將首先描述了事故的這些方面。2事故的性質和它們的統計特性事故基本概念是意外，不管是其發生的原因還是引起事故出現的過程。兩個簡單的假設通常是來描述

6、交通事故的形成過程：-事故發生的概率與以往發生的事故之間是獨立；-事故發生在時間上是同性質的如果這兩個假設成立，那么事故是泊松分布。第一個假設與大多數的批判不符。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為是一個個體事故但包含許多的車。這個假設并不適用于統計人員傷亡。傷亡人數往往與同一事故有關，因此，獨立性假設不成立。第二個假設乍一看似乎不太容易理解。穿越空間或在不同地點發生的的事故同樣具有可能性。然而，假設需要很長一段時間并且沒有緩繳期。其性質是根據理論的假設。如果其短時間內能成立，那么它也適用于長時間，因為泊松

7、分布變量的總和，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則等于為這些地方的泊松率的總和。假設與一個真正的情況相比較計數，無論是從一兩個結果還是總情況來看都有一個基本情況比較符合。例如，對比在一年中特定的一天例如下一天，下一個星期的一天發生的交通事故。如果條件是相同的（同一時間，交通情況相同，同樣的天氣條件等），那么由此產生的意外數字是相同的泊松過程的結果。這一假設可以通過估算進行測試的兩個觀測值的基礎上（估計是兩個值的平均值）的速度參數。概率理論能夠考慮到這兩個觀察值的平均，用于計算的平等假設的可能性。這是一個相當強大的統計過程。泊松假設是研究了很多次，來獲得證據支

8、持。它已經應用于許多情況，數的差異表明在安全性的差異然后確定是否發生意外。這一程序的主要目的是檢測在安全分歧。這可能是一個時間上的差異，或不同的地方或不同的條件。這種差異可以指導改進的過程。由于主要關注的是，以減少意外的發生，這種分析可能導致對治療中最有前途的領域。為這樣一個測試應用程序的必要條件是，那意外的數字進行比較是大到足以證明存在的分歧。在許多地方情況下，一個應用程序是不可能的。事故黑點分析往往阻礙了這一限制，例如，如果應用這種測試，找出事故是否在特定的位置數是高于平均水平。該程序的描述，也可以使用，如果發生意外乃根據數的特點找到有前途的安全目標。不僅聚集，而且還與分類泊松假設成立，而

9、意外數字可以相互測試的泊松假設的基礎。這種測試是相當麻煩的，因為每個特定的情況下，每一個不同的泊松參數，即，對所有可能結果的概率必須計算應用測試。然后，泊松分布近似為正態分布，均值和方差等于泊松參數。一旦均值和方差的正態分布，給出了所有的測試可以改寫了標準零均值和方差的正態分布條件。沒有任何更多的必要計算，但測試統計，需要利用表繪制。3. 行車安全政策事故統計的應用分析那些假設的基礎上描述的測試程序的類型及其優點。這種應用最好的例子是為一個國家或地區進行超過一年的安全監測，用事故的總體數據（最終的特定類型，如死亡事故）與前幾年的數據相比較。根據數年的事故序列，能夠分析出它的發展趨勢，并大致預測

10、以后幾年的事故數量。一旦建立了這樣一種趨勢，那么在誤差范圍內未來一年或幾年都可以預見。從一個給定趨勢的偏差也可以進行預測新的事件。最有名的是斯米德在1949年進行的分析。我們將討論這個事故類型分析更詳細的內容。1、該測試應用推廣到高階分類。foldvary和lane（1974），在衡量強制佩戴安全帶的效果，誰是最早應用于值的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的優勢。和2。比以前的情況是，這對許多相互關聯的（子）表和相應的智廣場卡方檢驗是由大量分析，取而代之的是一個一卡方的確切劃分。

11、 3、投入更多關注的是參數估計。例如，在卡方分割使人們有可能以測試有關行參數的線性或二次限制或趨勢的不連續性。4、分析的單位是從數到廣義加權計數。這對于道路安全分析，那里一段時間，道路使用者的數量，地點或公里數的車輛往往是必要的修正有利。最后一個選項是沒有發現在許多統計軟件包。安徒生1977年給出了一個用于道路雙向安全分析表的例子。工資保障運動的一個計算機程序。這一級沒有說明事故原因分析。它會嘗試檢測安全問題需要特別注意。所需的基本信息包括事故數字，來形容不安全總額，暴露的數據來計算風險，并找到一個高風險的情況下或（團體）道路使用者。 4. 事故分析研究目的交通安全的研究是有關的事故及其后果的

12、發生。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果本身，而是多在進程更多的結果（或不結果）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，結果是，該實際發生是由研究者未落觀測研究的主要問題。調查一宗交通意外，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情況，車輛，道路和司機的特點。因此這不是科學獨特的，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。有系統的控制實驗手段研究只對問題方面的可能，而不是問題本身。間接觀察和缺乏系統的控制組合使調查人員很難發現在什么情況

13、下造成事故的因素。雖然研究人員主要是在事故處理領導有興趣，他幾乎完全信息的后果，它的產品，意外。此外，事故背景是復雜的。一般來說，可分為以下幾個方面： -考慮到交通系統，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，意外可以或無法預防。 -由于發生事故，也對這樣的速度和車輛質量的因素，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，傷害是嚴重或或多或少物質損失是多還是少可觀。雖然這些方面不能獨立研究從理論的角度看，它也從由此產生的結果的優勢，區分交通情況有潛在危險的數字，是由有一個意外的可能性，在這種潛在的危險局勢，

14、給定一個特定事故。這個概念框架是對風險的關于個別道路使用者，以及上級的決定控制器的決定制定的一般基礎。在風險的數學公式，我們需要一個明確的概率空間的介紹，基本事件（的情況），可能導致事故組成，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，然后找出關鍵因素。這種類型的事故分析是通過分析事故的共組或子群來開展。事故本身是一個研究的單位，但也要研究道路因素：道路位置，道路設計（如一個彎道）等。原文出處：swov institute for road safety research leidschendam（會議記錄），記錄者，s.oppe

15、.possibilities and limitations of accident analysiss.oppekeyword：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 a

16、ccident developments, the 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 s

17、afety analysis on newly developed 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

18、 detection, combined with video 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

19、experience concerning traffic 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 alrea

20、dy elsewhere.from this lack of 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

21、at a real accident on video. 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 parti

22、cular car-car accident, that 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 c

23、oming almost to a stop and hit 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, bu

24、t was his view possibly blocked 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 disappea

25、red within five minutes, the 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 e

26、quipment and the recent developments 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 importa

27、nt to look at normal traffic 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 differen

28、t background and based on different 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 activi

29、ties in the area of traffic safety. 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 a

30、nd its main characteristics;- 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

31、/managerial or scientific) background 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 primaril

32、y interested in individual accidents. 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

33、 result.researchers are much more 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 th

34、is is the decrease in the total 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 app

35、lied in the area of traffic safety. 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

36、 describe this process for (traffic) 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 m

37、eet much criticism. accidents are rare 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.t

38、he assumption does not apply to casualties. 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. h

39、owever, the assumption need not hold 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 d

40、istributed. the poisson rate for the 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

41、of basic situations. e.g. , the comparison 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 con

42、ditions etc.) then the resulting numbers of 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

43、 likelihood of the equality assumption, given 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 o

44、ut whether differences in observed numbers 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 o

45、f improvement. because the main concern is 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.

46、in many local cases an application is not possible. 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 accident

47、s are classified according to a number of characteristics 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 c

48、umbersome, because for each particular case, 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 distrib

49、ution, with mean and variance equal to the 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

50、can be drawn from tables.3. the use of accident 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 ove

51、r a year, using the total number of accidents (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

52、predicted for following years. once such a trend 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

53、 discuss this type of accident analysis in more 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 partition

54、ing of the total chi-square in values for the 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 interac

55、tion effects of part tables. the advantage of 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 es

56、timation. e.g., the partitioning of the chi-square 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

57、 corrections for period of time, number of road 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 fo

58、r this type of analysis of multi-way tables, is 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 am

59、ount of unsafety, and exposure data to calculate 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 researchers interest however is less focused at this final outcome itself, but much more a