Built environment and pedestrian behavior at rail rapid transit stations in Bangkok

Urbanization and demands for mobility have spurred the development of mass rapid transit infrastructure in industrializing Asia. Differences between the character of pre-existing urban structure in these localities and worldwide precedents suggest a need for studies examining how new rapid transit systems function locally. This study of Bangkok’s elevated and underground rail systems identifies relationships between the built environment and pedestrian behavior surrounding stations. Based on details of 1,520 pedestrian egress trips from three elevated and three underground stations in 2006, multiple regression and analysis of variance (ANOVA) revealed that types of pedestrian destinations, reflecting land uses, were related to length of walking egress trips. Trips to shopping centers and office buildings were longer, while trips to eating places were shorter. The most common type of pedestrian trip recorded was to another vehicle, and trips to automobile taxis and motorcycle taxis figured prominently. Policy implications of the findings are considered.     

临床致病性不动杆菌的分子生物学鉴定

目的对临床致病性不动杆菌进行种属鉴定,并比较3种方法(44℃生长试验、特异性引物PCR扩增和16SrRNA测序)对鲍曼不动杆菌鉴定的特异性、准确性及应用价值。方法收集临床致病不动杆菌56株,首先接种在胰蛋白胨大豆肉汤中44℃进行培养,观察是否可以生长;其次,提取56株不动杆菌基因组DNA,用两组不同的特异性引物进行PCR扩增鉴定;最后,用通用引物对56株不动杆菌的16SrRNA进行测序鉴定。结果 56株不动杆菌中有17株可在44℃生长。经特异性引物PCR扩增鉴定,发现8株鲍曼不动杆菌和3株13TU型不动杆菌均可在44℃中较早较快生长。金标准16SrRNA测序确定56株不动杆菌中含有9个种,其中鲍曼不动杆菌和13TU型不动杆菌的鉴定结果与特异性引物PCR扩增法相同。结论应用分子生物学方法鉴定鲍曼不动杆菌具有准确、高效且可重复性高的优点,尤其是特异性PCR扩增法,可作为较难诊断的鲍曼不动杆菌的首选鉴定方法。     

What is the relationship between online activity and driving-licence-holding amongst young adults?

There is growing interest amongst both practitioners and researchers in the correlates of young adults’ driving-licence-acquisition. One aspect of the ongoing scholarly debate is whether taking part in online (i.e. virtual) activities may be associated with young adults feeling less need to drive and hence to acquire a driving licence. This paper addresses this issue by drawing on analysis of two distinct datasets. Both contain rich pseudo-diary instruments in which people indicate detailed characteristics of their unique online-activity profile. This includes both indicators of the types of online activities in which respondents participate, and a separate metric of internet-use intensity. The latter is defined in one dataset as the amount of time/week spent online, and in the other dataset the frequency of their internet use. On the basis of a set of multivariate regression analyses, a positive (i.e. complementary) cross-sectional relationship between young adults’ online activity and licence-holding was found. We find that young adults who use the internet are, net of confounding effects, more likely to hold a driving licence than otherwise identical young adults who do not use the internet. Both datasets show this type of effect, and it is robust across a range of model specifications, including multi-stage estimations to address cross-correlation between indicators of internet usage. In addition to the positive net statistical association, we also report several other noteworthy effects. Of the six effects associated with online-activity types that are directly comparable between the two datasets, we find that the correlation in the parameter estimates across the two datasets is 0.63. This suggests similar types of relationships across the two datasets. Also, in several (but not all) of our analyses we found an inverted ‘U’ shaped ceteris paribus relationship between intensity-of-internet-use and licence-holding. The positive net statistical association between internet use and licence-holding is a different relationship than previously reported in the literature, and therefore further research is needed to reconcile the differences (which are likely due at least in part to different methodological approaches and data resources). Further research is also needed to continue to resolve between the relative saliency of other hypothesised determinants of licence-holding (e.g. economic and socio-demographic explanators, as well as licence-acquisition regimes that vary by time and place).     

Tollroads are only part of the overall trip: the error of our ways in past willingness to pay studies

With rare exception, actual tollroad traffic in many countries has failed to reproduce forecast traffic levels, regardless of whether the assessment is made after an initial year of operation or as long as 10 years after opening. Pundits have offered many reasons for this divergence, including optimism bias, strategic misrepresentation, the promise to equity investors of early returns on investment, errors in land use forecasts, and specific assumptions underlying the traffic assignment models used to develop traffic forecasts. One such assumption is the selection of a behaviourally meaningful value of travel time savings (VTTS) for use in a generalised cost or generalised time user benefit expression that is the main behavioural feature of the traffic assignment (route choice) model. Numerous empirical studies using stated choice experiments have designed choice sets of alternatives as if users choose a tolled route or a free route under the (implied) assumption that the tolled route is tolled for the entire trip. Reality is often very different, with a high incidence of use of a non-tolled road leading into and connecting out of a tolled link. In this paper we recognise this feature of route choice and redesign the stated choice experiment to account for it. Furthermore, this study is a follow up to a previous study undertaken before a new toll road was in place, and it benefits from real exposure to the new toll road. We find that the VTTS is noticeably reduced, and if the VTTS is a significant contributing influence on errors on traffic forecasts, then the lower estimates make sense behaviourally.     

A Fisherman's Co-operative: Open System Theory applied ☆

In this paper the effects on the economic output, income and employment relating to Shetland are considered using an input—output model. The results are presented on the basis of an individual industry and appropriate multipliers are derived.     

Evaluating the long term impacts of transport policy: The case of passenger rail privatisation

Britain's national rail system was ‘privatised’ as a result of the 1993 Railways Act, with most of the organisational and ownership changes implemented by 1997. This paper examines the long term impacts of these changes. A key issue when examining long term changes is that of the counterfactual – what would have happened if the changes had not occurred? A simple econometric model of the demand for passenger rail services was developed and used in conjunction with extrapolative methods for key variables such as fares and train km to determine demand-side counterfactuals. Extrapolative methods were also used to determine counterfactual infrastructure and train operation costs. Although our results are sensitive to the assumptions we have made concerning the counterfactual they suggest a number of impacts. Since privatisation, rail demand has grown strongly but our analysis indicates that transitional disruptions suppressed demand by around 9% over a prolonged period (1992/3 to 2005/6), whilst the Hatfield accident reduced demand by about 5%, albeit over a shorter period (2000/1 to 2006/7). A welfare analysis suggests that although consumers seem to have gained as a result of privatisation, for most years this has been offset by increases in costs. An exception is provided by the two years immediately before the Hatfield accident. Overall the loss in welfare since the reforms were introduced far exceeds the net receipts from the sale of rail businesses. Thus although the reforms have had advantages in terms of lower fares and better service levels than otherwise would have been the case, this appears to have been offset by increased infrastructure and train operations costs. The source of these high costs remains an area of speculation but appear to be related to aspects of both market and regulatory failure.     

The perceived importance of employment considerations in the decisions of students to enrol on undergraduate courses in Maritime Business in Britain

In recent years, external pressures on maritime businesses have increased their need to employ high calibre personnel, educated to respond effectively to these pressures. Set against this requirement, the onus of acquiring a university education has shifted to the individual, as state subsidies to individuals seeking to undertake higher education in British universities have declined, and many corporate training programmes have been aimed at meeting the needs of an organization rather than the individuals within them. If the future supply of graduates is to match ongoing industrial requirements, one needs to understand why students enrol on particular courses, and how importantly they perceive employment considerations to be when making their decisions. This paper reports on a survey of why students at several British universities chose to enrol on undergraduate courses in Maritime Business, and considers the implications of its findings for ensuring that an adequate supply of suitably educated graduates will continue to be available to meet industrial needs.     

Workshop report - System development

The workshop considered system development as a key element of improving the performance of public transport. The main theme was the governance of decision making, design and development of public transport projects. A first main finding is that governance should be improved to keep focus on the original values for which the projects are started. Many projects lose sight of their original aims through the long and often problematic process from inception to operation. A second main finding is that the technological choice, mainly between rubber on tarmac and steel on rails, can be postponed, as both technologies start to overlap in their capacities. A stronger focus on functional needs in the earlier phases of the projects could help. Finally, as the different technologies provide similar options and can be used interchangeably, communicating the service they provide in other ways then through vehicle and infrastructure technology becomes more important.     

Residual stress distributions in ship hull specimens

This paper provides an in-depth study of residual stress distributions found in stiffened steel plate structures, such as those typically used in ship hulls. The effect of stiffener spacing on the distribution of residual stress components was studied. The welding heat input was also varied between high and moderate to study the effect of heat input level on residual stress distributions. Four specimens, resembling typical stiffened steel plate structures used in ship hulls were built and tested. Steel plates of 9.5 mm thickness were stiffened by welding L127 × 76 × 9.5 steel angles. The test was completed using the neutron diffraction method. The three normal components of residual stress were obtained in this study. It was found that a lower heat input results in higher tensile residual stress and that there exists a critical stiffener spacing somewhere beyond 250 mm that creates a maximum tensile residual stress value near the welded connection.     

How much noise reduction at airports?

Airport noise nuisance is a negative externality especially when it occurring near urban areas. Like all externalities, noise nuisance may be a reason for government intervention. When intervening, governments should set quantitative policy targets with care. In practice, this issue is generally neglected. This line of research sets the first step towards determining optimal policy targets in the case of noise nuisance near airports, more specifically in the case of Amsterdam Airport. We use hedonic pricing to establish the benefits of noise reduction. Furthermore, we develop a bottom-up cost function to analyze the costs of reducing noise for airlines. We then equate marginal costs and benefits to establish the optimal level of noise reduction, which appears to be 3 dB in the case of Amsterdam Airport. Welfare increasing measures include alternative approach procedures, regional substitution of planes within existing fleets and early depreciation of noisy planes increase welfare. Reducing the number of flights has a negative effect on net welfare.