807 research outputs found

    Costs of Interchange: A Review of the Literature.

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    Interchange within mode influences the demand for that mode through the effect it has on time spent waiting, time spent transferring between vehicles and the inconvenience and risks involved, whilst interchange between modes has additional implications in terms of information provision, through ticketing and co-ordination. The valuation and behavioural impact of each of these factors will vary with an individual’s socio-economic and trip characteristics as well as with the precise features of the interchange. A reduction in the costs of interchange brought about by an improvement to any of the above factors will lead to increasingly ‘seamless journeys’ and such benefits which must be quantified. Indeed, this issue has been identified as an area of key importance in the Government’s Transport White Paper (DETR, 1998a) which states: Quick and easy interchange is essential to compete with the convenience of car use. This message was reiterated by the draft guidance for Local Transport Plans (DETR, 1998b), which called for: more through-ticketing, better connections and co-ordination of services, wider availability of information and improved waiting facilities. Rather than being perceived simply as a barrier to travel, quality interchange is now also being regarded as an opportunity to create new journey opportunities. A recent report on the subject of interchange (Colin Buchanan and Partners, 1998) claimed that : It will become more sensible and economic to base public transport networks around the concept of interchange rather than the alternative of trying to avoid it. whilst in response to the diffuse travel patterns made possible by increased car availability, CIT (1998) commented: people should readily be able to complete a myriad of journeys by changing services (and modes) if a through facility is not available. Ease of interchange should be something we take for granted. Regardless of the precise direction in which transport policy and public transport provision develop, practical constraints and the fact that the most heavily trafficked routes tend to have through services places limitations on the extent to which the need to interchange can be reduced whilst no matter how fully integrated different modes of transport are the need to transfer between them cannot be removed. In contrast, the need to change would inevitably increase with the adoption of a practice of building networks around interchange to create new journey opportunities. However, there is considerable scope to improve existing interchange situations or to design new ones which impose minimum costs. Although previous empirical research has focused on the need to interchange or not, and this remains important, it is essential that research is also directed at improvements which facilitate interchange.The aims of this study, as set out in the terms of reference, are centred around the demand side response to interchange rather than the technical supply side issues relating to improving interchange and integration which have been covered in other studies (Colin Buchanan and Partners, 1998; CIT, 1998). The objectives are: to explore the extent to which the reality and perception of interchange deters public transport use, absolutely and in relation to other deterrents to investigate how public transport users perceive interchange; how they make choices and trade-offs in travel cost and time and the influence of interchange attributes (e.g. information, through ticketing) on those choices to assess which components of interchange act as the greatest deterrent to travel to investigate the extent to which interchange penalties vary according to journey purpose, distance and time of travel (or other factors)

    Econometric modelling of competition between train ticket types

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    INTRODUCTION The railways in Britain have a long history of using price discrimination backed up with product differentiation to significantly increase revenue over what might be obtained in an undifferentiated market. Whilst not as sophisticated as the yield management systems widely used in the airline industry, rail ticketing strategies are continually evolving, with new products emerging, unsuccessful products discontinued and gradual refinement of others. In recent years, there has been increased interest in modelling competition between different ticket types. The re-organisation of the railway industry in Great Britain has provided a greater commercial incentive to operators to price differentiate in order to maximise the revenue from their franchises. The policy of moderation of competition has allowed limited on-track competition, largely based around overlapping franchises but also with service extensions and new entrants, and this has stimulated product development and hence interest in ticket choice. Partly in response to the greater commercialisation of the railway industry, particularly where here is a degree of market power, the regulatory bodies have taken a greater interest in the range of tickets offered and their associated prices, travel restrictions and availability (SRA, 2003). This paper reports on research which was conducted as part of an update to the Passenger Demand Forecasting Handbook (PDFH), which contains a forecasting framework and recommended demand parameters that are widely used in the railway industry in Great Britain (ATOC, 2002), and as part of a project to provide the Strategic Rail Authority with evidence on cross elasticities between ticket types for use in its review of how it regulates rail fares

    Demand Forecasting for New Local Rail Services: A Case Study of a New Service Between Leicester and Burton-On- Trent

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    Preston, J. and Wardman, M. (1988) "Demand Forecasting for New Local Rail Services: A Case Study of a New Service between Leicester and Burton-on-Trent". Workina Paver 260, Institute for Transport Studies, University of Leeds. This paper assesses the potential for a new rail service between Leicester and Burton-on-rent. In order to do this, three sets of demand forecasts were produced. These were based on Revealed Preference (RP) models that had been developed in West Yorkshire, a Stated Intentions (SI) survey of the Leicester-Burton corridor and Stated Preference (SP) models developed for the Ashby/ Coalville -and Outer Leicester areas. It was found that these three approaches gave a wide range of forecasts but it was felt that the SI survey, adjusted for the findings from the SP models, were likely to give the most reliable estimates of usage. As a result, it was concluded that, given patronage growth over time, total usage of the line would amount to between 3,000 and 4,000 trips on an average day. The demand forecasts were then used as input to an evaluation framework which took into account capital costs, operating costs, revenue and time savings. Even if actual usage reached the upper level of our forecasts it was shown that, although operating costs would be covered, only some of the capital costs would be paid back. Consideration of user time savings strengthens the case for the scheme but even so a return on capital would still not be achieved. Therefore, it was concluded that the case for a rail service between Leicester and Burton is, at best, marginal, although a number of ways to continue the feasibility study are suggested

    Stated Preference Analysis of Driver Route Choice Reaction To Variable Message Sign Information

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    Highway Authorities in many parts of the world have, for some years, been using variable message panels mounted above or beside the camageway to communicate short messages to motorists. Most such applications have been concerned with hazard warning and speed advice. However, their use to deliberately affect route choice is an area of great current interest. It is recognised that they have a potential role in managing demand to match the capacity available, not only to alleviate acute problems caused by roadworks and accidents, but also to contribute to satisfactory performance of networks operating close to capacity over extended periods of high, but variable, demand. The installation and operation of the panels is not cheap and there is a widespread belief that overuse, or inappropriate use, of the messages may lead to them losing their credibility with the motorists and thus ceasing to be effective. It is therefore very important to understand the likely response of motorists to various messages before displaying them and even before selecting sites for the installation of panels. A number of researchers have explored drivers' responses to traffic information and route advice offered via variable message signs (VMS). Evidence from traffic counts suggests that messages can persuade somewhere between 5% and 80% of drivers to divert. Clearly this range of estimates is far too wide to support the use of VMS for fine tuning the pattern of demand. A major contributor to the uncertainty, however, is the varying, and often unknown, proportion of drivers whose destination makes the message relevant to them. More detailed studies involving driver interviews downstream of the VM!3 site to determine the relevance of the message, as well as the response to it, include those by Kawashima (1991) and Durand-Raucher et al. (1993). These studies have produced more precise estimates of compliance but the results are obviously limited to those messages which were on display at the time the interviews were being conducted. A number of researchers have sought to overcome this restriction by examining response to a range of messages presented via a stated preference exercise (see for example Hato et al., 1995; Shao et al., 1995 and Bonsall and Whelm, 1995), via a route-choice-simulator (see for example Firmin, 1996; Bonsall and Merrall, 1995 ; Bonsall and Palmer, 1997) or via a full scale driving simulator or system mock-up (see for example Mast and Ballas, 1976 and Brocken and Van der Vlist, 1991). This research has suggested that response is highly dependent on message content, subjects' network knowledge, and on the extent of any implied diversion. We see particular value in extending this earlier work to consider a wider range of messages and to determine whether the route-choice-simulator results can be repeated and extended using a somewhat cheaper methodology - namely stated preference analysis. The objectives of the work reported in this paper were thus: to extend to our existing database on drivers' response to traffic information and route advice provided in variable message signs, to include a wider range of messages. to construct explanatory models of drivers' route choice behaviour in response to a variety of messages to explore the factors influencing this response to compare these results with previous results obtained using a variety of data collection methods to draw policy conclusions, where appropriate, on the use of variable message signs to influence drivers' route choice to draw conclusions, where appropriate, on our data collection and modelling methodology

    Undergraduate leadership education for dentistry: preparing for practice

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    This paper seeks to explore the topic of leadership education in undergraduate dental programmes. ‘Management and leadership’ has been recognised as one of the four main domains in the UK General Dental Council ‘Preparing for Practice’ document and is identified in the ADEE ‘Profile and Competences for the Graduating European Dentist’ document under the domain of ‘Professionalism’. Many dental schools throughout Europe are now planning for the inclusion of leadership education. Questions are therefore raised about how this might be envisaged: what should undergraduates be prepared for and how should it be done? This paper draws on emerging debates found within the wider, non-dental specific leadership studies literature that challenge traditionally held views of leadership and models of leadership education found currently in dentistry. It is argued that all students should be exposed to distributed and inclusive leadership practices to prepare them for the challenges they will find in their everyday practising careers. It is proposed that there is an opportunity to engage with dental practitioners (at all levels) to encourage the development of experiential, active learning to bring alive leadership in practice for dental students

    Valuation of aircraft noise by time of day: a comparison of two approaches

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    This paper reports an innovative application of stated preference techniques to derive values of aircraft noise by time of day and day of week. Revealed preference techniques cannot provide such segmentations which would clearly be of use in policy development especially relating to airport operations. Given the lack of research on this issue the work reported here is highly experimental. Two stated preference experiments were designed. The first focussed on a single time period whilst the second asked respondents to trade between time periods. Both approaches yielded results that are plausible and mutually consistent in terms of relative values by time period. We conclude that stated preference techniques are particularly useful in this context where the use of aggregated values may lead to non-optimal policy decisions

    The use of recovery time in timetables: rail passengers' preferences and valuation relative to travel time and delays

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    Recovery time in the rail industry is the additional time that is included in train timetables over and above the minimum journey time necessary often with the explicit aim of improving punctuality. Recovery time is widely used in railways in a number of countries but prior to this study there has been no investigation of the rail users’ point of view. Perceived recovery time, such as being held outside stations and prolonged stops at stations, might have some premium valuation due to the frustration caused. If perceived recovery time in train timetables does carry a premium, then the benefits of improved punctuality achieved by it will be reduced. This paper is the first to investigate passengers’ views and preferences on the use of recovery time. We summarise the findings of a large study and provide estimates of passengers’ valuations of recovery time, both relative to in-vehicle time and late time, that can be used for economic appraisal purposes. Overall, we find most passengers support the use of recovery time but the context is important. Only 13% of users disapprove of its use as a tool to reduce lateness. The estimated premia vary by demand characteristics and are significant in some contexts, although on average are of a small magnitude. The applicability of the estimates is demonstrated through the appraisal of an actual scheme in the UK. We observe that the introduction of more recovery time along with the subsequent improvement in reliability can lead to significant reductions in generalised journey time, even when recovery time carries a valuation premium. We must however strike a word of caution since we note that there were higher than expected proportions of non-traders in the survey which may have affected the results; future studies into the topic should look to minimise the proportion of non-traders. This study provides valuable and necessary first steps in this challenging topic

    Ceftazidime-avibactam or best available therapy in patients with ceftazidime-resistant Enterobacteriaceae and Pseudomonas aeruginosa complicated urinary tract infections or complicated intra-abdominal infections (REPRISE): a randomised, pathogen-directed, phase 3 study

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    Background Carbapenems are frequently the last line of defence in serious infections due to multidrug-resistant Gram-negative bacteria, but their use is threatened by the growing prevalence of carbapenemase-producing pathogens. Ceftazidime-avibactam is a potential new agent for use in such infections. We aimed to assess the efficacy, safety, and tolerability of ceftazidime-avibactam compared with best available therapy in patients with complicated urinary tract infection or complicated intra-abdominal infection due to ceftazidime-resistant Gram-negative pathogens. Methods REPRISE was a pathogen-directed, international, randomised, open-label, phase 3 trial that recruited patients from hospitals across 16 countries worldwide. Eligible patients were aged 18–90 years with complicated urinary tract infection or complicated intra-abdominal infection caused by ceftazidime-resistant Enterobacteriaceae or Pseudomonas aeruginosa. Patients were randomised (1:1) to 5–21 days of treatment with either ceftazidime-avibactam (a combination of 2000 mg ceftazidime plus 500 mg avibactam, administered via a 2-h intravenous infusion every 8 h) or best available therapy. The primary endpoint was clinical response at the test-of-cure visit, 7–10 days after last infusion of study therapy, analysed in all patients who had at least one ceftazidime-resistant Gram-negative pathogen, as confirmed by the central laboratory, and who received at least one dose of study drug. Safety endpoints were assessed in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01644643. Findings Between Jan 7, 2013, and Aug 29, 2014, 333 patients were randomly assigned, 165 to ceftazidime-avibactam and 168 to best available therapy. Of these, 154 assigned to ceftazidime-avibactam (144 with complicated urinary tract infection and ten with complicated intra-abdominal infection) and 148 assigned to best available therapy (137 with complicated urinary tract infection and 11 with complicated intra-abdominal infection) were analysed for the primary outcome. 163 (97%) of 168 patients in the best available therapy group received a carbapenem, 161 (96%) as monotherapy. The overall proportions of patients with a clinical cure at the test-of-cure visit were similar with ceftazidime-avibactam (140 [91%; 95% CI 85·6–94·7] of 154 patients) and best available therapy (135 [91%; 85·9–95·0] of 148 patients). 51 (31%) of 164 patients in the ceftazidime-avibactam group and 66 (39%) of 168 in the best available therapy group had an adverse event, most of which were mild or moderate in intensity. Gastrointestinal disorders were the most frequently reported treatment-emergent adverse events with both ceftazidime-avibactam (21 [13%] of 164 patients) and best available therapy (30 [18%] of 168 patients). No new safety concerns were identified for ceftazidime-avibactam. Interpretation These results provide evidence of the efficacy of ceftazidime-avibactam as a potential alternative to carbapenems in patients with ceftazidime-resistant Enterobacteriaceae and P aeruginosa. Funding AstraZeneca

    Accurate, precise modeling of cell proliferation kinetics from time-lapse imaging and automated image analysis of agar yeast culture arrays

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    BACKGROUND: Genome-wide mutant strain collections have increased demand for high throughput cellular phenotyping (HTCP). For example, investigators use HTCP to investigate interactions between gene deletion mutations and additional chemical or genetic perturbations by assessing differences in cell proliferation among the collection of 5000 S. cerevisiae gene deletion strains. Such studies have thus far been predominantly qualitative, using agar cell arrays to subjectively score growth differences. Quantitative systems level analysis of gene interactions would be enabled by more precise HTCP methods, such as kinetic analysis of cell proliferation in liquid culture by optical density. However, requirements for processing liquid cultures make them relatively cumbersome and low throughput compared to agar. To improve HTCP performance and advance capabilities for quantifying interactions, YeastXtract software was developed for automated analysis of cell array images. RESULTS: YeastXtract software was developed for kinetic growth curve analysis of spotted agar cultures. The accuracy and precision for image analysis of agar culture arrays was comparable to OD measurements of liquid cultures. Using YeastXtract, image intensity vs. biomass of spot cultures was linearly correlated over two orders of magnitude. Thus cell proliferation could be measured over about seven generations, including four to five generations of relatively constant exponential phase growth. Spot area normalization reduced the variation in measurements of total growth efficiency. A growth model, based on the logistic function, increased precision and accuracy of maximum specific rate measurements, compared to empirical methods. The logistic function model was also more robust against data sparseness, meaning that less data was required to obtain accurate, precise, quantitative growth phenotypes. CONCLUSION: Microbial cultures spotted onto agar media are widely used for genotype-phenotype analysis, however quantitative HTCP methods capable of measuring kinetic growth rates have not been available previously. YeastXtract provides objective, automated, quantitative, image analysis of agar cell culture arrays. Fitting the resulting data to a logistic equation-based growth model yields robust, accurate growth rate information. These methods allow the incorporation of imaging and automated image analysis of cell arrays, grown on solid agar media, into HTCP-driven experimental approaches, such as global, quantitative analysis of gene interaction networks

    Effectiveness of communications in enhancing adherence to public health behavioural interventions: a COVID-19 evidence review

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    Health communication has relevance for virtually every aspect of health and well-being, including disease prevention. This review explored the effectiveness of communications in enhancing the adoption of or adherence to behavioural interventions (non-pharmaceutical interventions (NPIs)) related to COVID-19. The review takes the UK as a case study and focuses on self-reported behaviours (e.g. social distancing). It also reviews the psychosocial determinants of adherence. Searches were conducted using PubMed, Scopus, CINAL, ASSIA and iCite databases. Eleven thousand five hundred records were identified and 13 were included in the final sample. Included studies suggest that NPI adoption or adherence was generally high, and communication had significant impacts, with key themes including clarity and consistency, trust and control. Based on the evidence in this review, features of effective communication in the context of NPI adoption or adherence are (i) information should be conveyed clearly and conflicting (mixed) messages should be avoided; (ii) information should be conveyed by trusted sources (e.g. health authorities) and (iii) communication should strike a balance between being authoritative but avoiding language seen as controlling (e.g. ‘you must’). Future research should prioritize quantitative, experimental and longitudinal study designs, that focus specifically on communication as an intervention, and which measure behaviour. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.</jats:p
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