求高手翻译,毕业论文
Megan3
Conclusions: What can be achieved?
It is undoubtedly possible, given a well planned programme of traffic counts,with an adequate screenline and control sites, and a serendipidous absence of confounding exogenous influences, to identify any increased traffic on the scheme link and to determine what proportion of this is due to rescheduling and rerouting. Such a program need not cost more than a few tens of thousands of pounds and should achieve a precision of around _+4% with 95% confidence depending on the timing of the surveys. Greater precision should become possible as our knowledge of the underlying variability in flow data improves.??Life gets much more difficult if one wants to distinguish b广告een the components of induced traffic.
Change of mode could, in theory, be identified fairly straightforwardly but when the difficulty of obtaining reliable patronage data and the probability that other factors (such as fares changes or service reorganisations) will he affected demand over the same period, is combined with the small effect expected, the prospects of achieving reliable results are not very encouraging.
We he seen how, with a programme of counts enhanced by carefully targeted interviews, it may be possible to distinguish b广告een redistribution and increased frequency but this can only be achieved at considerable cost and is very subject to exogenous influences. It is the current author's opinion that, where the possibility exists of land use effects, it is likely to be impossible ever to establish adequate control studies and hence impossible to distinguish b广告een the effects of the scheme itself and those of other influences. Even when a statistically significant effect can be established,the fact that individual transport schemes are rarely introduced in isolation
from other measures and initiatives, it is likely to make the attribution of cause difficult or impossible.
It is important that adequate surveys be conducted and objectively reported because, if there is room to doubt the findings, it is clear that there are those on either side of the debate who will be happy to do so. We he suggested that it should be possible to produce persuasive evidence as to the existence or otherwise of increases in demand which are not simply due to rerouting but we he concluded that the identification of the separate components of this extra traffic will be very difficult.
If the term "induced traffic is to be reserved for situations where there has been an increase in trip frequency, it follows that statistically robust evidence of induced traffic will rarely, if ever, be achievable from surveys and it is unlikely that such evidence as is produced will persuade the determined sceptics.