1,194 research outputs found

    Valuing the Attributes of Freight Transport Quality: Results of the Stated Preference Survey

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    This paper presents the results of a survey of fifty firms transporting ten commodity groups, using an interactive stated preference game to obtain values of the rate reduction necessary to compensate for longer transit times, poorer reliability and the use of intermodal systems. Generally, the pattern of results is as expected, with the quality of the transport service being less important for low value products in industries with high levels of stockholding, and vice versa. Quality requirements are also generally less stringent when products are moving to depots than to customers. In a critique of the method, some reservations are expressed both about the reliability of the results, andabout the high cost and time of the survey method. Nevertheless, we conclude that overall the approach has worked reasonably well, and yielded much valuable data; we know of no alternative method which could have yielded quantitative valuations in these circumstances

    Taxation of Road Goods Vehicles – An Economic Assessment

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    This paper reviews the current position, recent research and potential future areas of research relating to road track costs, with particular reference to Heavy Goods Vehicles. It opens with a theoretical discussion, which concludes that the appropriate basis for changing is long run marginal social cost, but casts some doubt on whether the existing cost allocation procedure achieves this. The main reason for this is the likelihood that the marginal capital cost per unit of traffic of coping with an increase in traffic volumes greatly exceeds the average capital cost per unit of traffic at the present time. The DTp method of allocating track costs is then outlined, and the sensitivity of the results to variations in a number of the key assumptions is tested. The results show that the DTp method may only be allocating HGVfs as little as half of their costs. Hence instead of covering their allocated costs by some 30% to allow for environmental effects, as the DTp. claim, it may be that these lorries are only meeting 65% of their allocated cost. The sensitivity tests that yield the above results reflect the following concerns: (1) FUEL CONSUMPTION DTp measures lorry mileage and deduces fuel used and hence fuel tax paid. However, their fuel consumption figures look implausibly high. We have used FTA figures instead. (2) TRAFFIC FLOW DTp currently allocate many costs to vehicle kilometres (e.g. drainage, winter maintenance, traffic signs etc.), but accepts that the demand for a new road arises in proportion to PCUs (passenger car units), i.e. giving more weight to lorries. Our view is that once a road is opened any general costs involved in its continued use should also be allocated by PCUs. (3) LORRY WEIGHTS DTp use lorry weights as reported on a self completion questionnaire, which naturally omit any overloading. We have used observed values from a large study in Cheshire. (4) CAPITAL EXPENDITURE DTp charge only what is currently being spent. Following cutbacks in all government expenditure, this amount is now some 50% lower than in the early 1970s. Since capital expenditure was roughly 60% of total road expenditure, this implies that cost allocations have fallen by 30% on this account. Our view is that even this understates the true long run marginal cost of road traffic. Although the precise figures are subject to much doubt, in every case there seems good reason to suppose that the proposition is broadly correct. Taken cumulatively, they would be sufficient to convert the existing overpayment by HGVs (which presumably is intended to reflect unquantified environmental costs) into a substantial underpayment. If the increase in road haulage taxation which these figures would imply is politically unacceptable, then there is a good case for corresponding action to relieve the rail and water modes of part of their infrastructure costs

    The track and external costs of road transport

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    1.1.1 The purpose of this study is to review: i) Developments in methodology and data regarding issues such as vehicle delay, accidents, overloading and valuation of environmental effects. ii) The likely effect of harmonisation of taxes within the European Community. iii) Future prospects regarding the level of spending on roads. iv) Alternative methods of dealing with social costs, including lorry routing, regulation and subsidy. v) Experience elsewhere in Western Europe and in North America. 1.1.2 We review the theory behind the allocation of road infrastructure costs, finding a number of items on which the current British approach can be criticised, in particular the treatment of capital costs on a pay-as-you-go basis. Comparisons with other countries suggest that the British system is relatively sophisticated, but this and other evidence suggests that the proportion of capital costs of new roads allocated to heavy vehicles is too low. 1.1.3 A spreadsheet model of the current British track costs allocation system is constructed, and the effects tested of proposed increases in road spending, of overloading, of the allocation those items of cost currently allocated on a vehicle km basis in accordance with pcu km and of the allocation of the external costs of accidents. It is found that, even without adjusting the treatment of capital costs, an increase in taxes on the heaviest lorries of some 30 % is justified, and on buses 60%. Evidence on the values of vehicle delay and environmental costs is examined but it is considered that these factors are not yet sufficiently well quantified to test the adequacy of the current 30% margin to allow for them. More work in this area is recommended. 1.1.4 The possibilities for harmonisation of vehicle taxation within the European Community are considered. Since Britain has a far higher level of taxation than most other European countries, any move towards harmonising tax levels would reduce taxes in Britain at a time when they should be increasing. Such moves should be resisted, but if they come then there would be a case for compensating action to relieve competing modes of part of their infrastructure costs

    New Inter-Modal Freight Technology and Cost Comparisons

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    Freight carried by rail has traditionally been mainly low value bulk commodities. As Western economies advance the market for such freight services is at best static, and forms a smaller proportion of the total demand for freight transport. There is thus an urgent need for British Rail and other rail systems to develop practical and cost effective inter-modal systems, which offer high quality services to consignors of consumer goods whose premises are not usually connected to the rail network. The new developments are of two types. Either they involve transferring the body of a road vehicle from road to rail, or moving the complete semi-trailer of an articulated outfit by rail. Each system has disadvantages in terms of volume or tare weight when compared to road, but each system may attract different commodities. Though the costs of inter-modal systems vary, their cost structures have similarities, consisting of collection and delivery costs, terminal, and rail movement elements. The break- even distance of each system depends on the extent to which low rail haulage charges offset the other costs incurred. However, traffic will only be attracted to inter-modal in sufficient quantities to enable viable services to be provided over a limited number of long distance routes. These services must also approach, if not equal the competition in terms of quality of service attributes, particularly reliability, if they are to overcome customer resistance. To assess the distances over which these new inter-modal systems will be cost competitive a cost model has been developed. The paper decribes how the model works, and the sources from which data was obtained. A separate paper (Working Paper 276) reports on a study to find the value placed by shippers on quality of service attributes, and a third paper (Working Paper 286) brings the two together to reach conclusions on the future role of inter-modal systems

    Disaggregated Approaches to Freight Analysis: A Feasibility Study.

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    Forecasting the demand for freight transport is notoriously difficult. Although ever more advanced modelling techniques are becoming available, there is little data available for calibration. Compared to passenger travel, there are many fewer decision makers in freight, especially for the main bulk commodities, so the decisions of a relatively small number of principal players greatly influence the outcome. Moreover, freight comes in various shapes, sizes and physical states, which require different handling methods and suit the various modes (and sub-modes) of transport differently. In the face of these difficulties, present DTp practice is to forecast Britain's freight traffic using a very simple aggregate approach which assumes that tonne kilometres will rise in proportion to GDP. Although this simple model fits historical data quite well, there is a clear danger that this relationship will not hold good in the future. The relationship between tonne kilometres and GDP depends on the mix of products produced, their value to weight ratios, number of times lifted and lengths of haul. In the past, a declining ratio of tonnes to GDP has been offset by increasing lengths of haul. This has come about through a complicated set of changes in product mix, industrial structure and distribution systems. A more disaggregate approach which studies changes in all these factors by industrial sector seems likely to provide a better understanding of the relationship between tonne kilometres and GDP. However, there are also problems with disaggregation. As we disaggregate we get more understanding of what might change in the future, but are less able to project trends forward. This can be seen if we consider the future amounts of coal movements. Theoretically there is clearly scope for better forecasting by allowing for past trends to be overturned by a movement towards gas powered electricity generation and more imports of coal direct to coastal power stations. However, making such a sectoral forecast is extremely difficult, and inaccuracy here may more than offset the theoretical gain referred to earlier. This is because it is usually easier to forecast to a given percentage accuracy an aggregate rather than its components. For example, the percentage error on sales forecasts of Hotpoint washing machines will be greater than that for the sales of all washing machines taken together. This occurs because different makes of washing machines are substitutes for each other, so forecasts for Hotpoint washing machines must take into account uncertainty over Hotpoint's market share as well as uncertainty over the future total sales of washing machines. Nevertheless, a disaggregate investigation of the market could spot trends which were `buried' in the aggregate figures. For example, rapidly declining sales for one manufacturer might indicate their leaving the market, which with less competition would then price up and so reduce the total future sales. We have assumed above that the use of the term disaggregate in the brief refers to disaggregation by industrial sector. An alternative usage of the word disaggregate in this context is when referring to modelling at the level of the individual decision making unit. Disaggregate freight modelling in this sense would involve analysing decisions in order to determine the utility weight attached to different attributes of available transport options. Because data on suitable decisions is not readily available in this country, due to commercial confidentiality, we have recently undertaken research in which we have presented decision makers with hypothetical choices, and obtained the necessary utility weights from their responses. Whilst initial scepticism is understandable, this method has produced results acceptable for use in major projects. ITS itself has provided algorithms (known as Leeds Adaptive Stated Preference) which have been used to derive utility weights for use by British Rail in forecasting cross-channel freight, by DTp in evaluating the reaction of commercial vehicles to toll roads, and by the Dutch Ministry of Transport in modelling freight in the Netherlands. In the light of the above, the following objectives were set for the feasibility study: (1)To determine if a forecasting approach disaggregated by industrial sectors, as under the first definition above, can be used to explain recent trends in freight transport; (2)To test the feasibility of the disaggregated approach for improving the understanding of likely future developments in freight markets, this being informed by current best understanding of the disaggregate decision-making process as under the second definition above

    How highly does the freight transport industry value journey time reliability - and for what reasons?

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    Delays to road freight vehicles impose a very high cost on the nation. Delayed arrival time can occur for a variety of reasons. This paper presents the findings of a Highways Agency funded study, which has investigated the user valuations of three different kinds of delay: • A delay resulting from an increased journey time, with fixed departure time • An increase in the spread (or range) of arrival times for a fixed departure time • A schedule delay where the departure time is effectively put back. The paper summarises the findings of the study, which centred on an interview survey of forty shippers, hauliers and third party logistics operators. Respondents were asked to consider one of their freight flows on the trunk road network in detail. Various reasons why respondents value a high degree of predictability of journey times on the trunk road network are identified and discussed. The paper then moves on to present and discuss user valuations of each kind of delay, estimated using the Leeds Adaptive Stated Preference (LASP) methodology

    PMI: A Delta Psi(m) Independent Pharmacological Regulator of Mitophagy

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    Mitophagy is central to mitochondrial and cellular homeostasis and operates via the PINK1/Parkin pathway targeting mitochondria devoid of membrane potential (ΔΨm) to autophagosomes. Although mitophagy is recognized as a fundamental cellular process, selective pharmacologic modulators of mitophagy are almost nonexistent. We developed a compound that increases the expression and signaling of the autophagic adaptor molecule P62/SQSTM1 and forces mitochondria into autophagy. The compound, P62-mediated mitophagy inducer (PMI), activates mitophagy without recruiting Parkin or collapsing ΔΨm and retains activity in cells devoid of a fully functional PINK1/Parkin pathway. PMI drives mitochondria to a process of quality control without compromising the bio-energetic competence of the whole network while exposing just those organelles to be recycled. Thus, PMI circumvents the toxicity and some of the nonspecific effects associated with the abrupt dissipation of ΔΨm by ionophores routinely used to induce mitophagy and represents a prototype pharmacological tool to investigate the molecular mechanisms of mitophagy

    Characteristics and Treatments of Patients with Peripheral Arterial Disease Referred to UK Vascular Clinics: Results of a Prospective Registry

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    BackgroundPeripheral arterial disease (PAD) is often associated with risk factors including cigarette smoking, hypertension and hypercholesterolaemia, and patients have a high risk of future vascular events. Good medical management results in improved outcomes and quality of life, but previous studies have documented sub-optimal treatment of risk factors. We assessed the management of cardiovascular risk factors in patients with PAD referred to specialist vascular clinics.MethodsThis was a prospective, protocol driven registry carried out in UK vascular clinics. Patients who were first-time referrals for evaluation of PAD were eligible if they had claudication plus ankle-brachial pressure index (ABPI) ≤0.9. Statistical associations between key demographic and treatment variables were explored using a chi-squared test.ResultsWe enrolled 473 patients from 23 sites. Mean age was 68 years (SD 10) and 66% were male. Mean estimated claudication distance was 100m, and ABPI was 0.74. Mean systolic blood pressure (SBP) was 155mmHg, and 42% had a SBP >160mmHg. Forty percent were current smokers and half had tried to give up in the prior 6 months, but there was no evidence of a systematic method of smoking cessation. Mean total cholesterol was 5.4 (SD1.2) mmol/l and 30% had levels >6mmol/l. Antiplatelet therapy had been given to 70% and statins to 44%. Prior CHD was present in 29% and these patients had significantly higher use of antiplatelet therapy, statins and ACE-inhibitors.ConclusionsIn spite of attempts to raise awareness about PAD as an important marker of cardiovascular risk, patients are still poorly treated prior to referral to a vascular clinic. In particular, the use of evidence-based treatments is sub-optimal, while hypertension and cigarette smoking are poorly managed. More work needs to be done to educate health professionals about the detection and optimal medical management of PAD