The Distributional Impact of Various Road Charging Schemes for London.

This Working Paper presents results obtained using the MVA START model for London, with the primary intention of investigating the distributional impact of road pricing in various forms and at various levels. In order to look at distributional effects the START model had to be 'disaggregated' by income groups - three each for non-car owning and car-owning households. Initially, this allowed us to see the distributional impact of the LPAC Preferred Strategy, mainly involving public transport and traffic management policies. Beyond this we tested three structures (or 'regimes') of road pricing, varying from a complex three cordon plus screenlines structure, to a single Central London cordon. Somewhat surprisingly, the latter was found to be regressive in its application. The structure with the highest benefits, as well as being relatively progressive, was the complex structure of three cordons plus screenlines, with an optimum charge level of 50 pence per cordon crossing, each way but with the outer two cordons being peak only

The Optimisation of Integrated Urban Transport Strategies: Tests Based on Edinburgh

INTRODUCTION Even with relatively simple model packages and modern computers, it is not feasible to test all combinations of model input variables to see which combination gives the 'best' outcome. Neither is it usually possible to solve the models analytically for the optimum. Consequently, there is a potential role for a methodology which takes as input the results from a relatively small number of runs of the model package and then models the response surface in the region containing the optimum, in such a way that it can be analytically solved for the optimum. This paper will set out such a methodology together with a Case Study

The Optimisation of Integrated Urban Transport Strategies: Tests Using Pluto

This working paper reports work indertaken on an EPSRC study, the optimisation of integrated urban transport strategies. It is the fist in a series of papers each reporting work using a different transport model. This paper is concerned with work using PLUTO, a transport model based on a hypothetical city, which can provide model runs quickly and cheaply. PLUTO was used to experiment widely, examining paths towards an optimum when considering discrete policy variables, continuous policy variables and hybrids where several policy variables may be combined to form a strategy. Our search for a method by which to reach an optimum solution uses regression analysis of carefully specified sets of model runs. We find that the use of statistical modelling techniques is extremely useful in pointing the way to an optimum, using only a limited number of model runs. However, care is necessary to ensure that the regression models are interpreted correctly

An Investigation Into the Effects of Various Transport Policies on the Levels of Motorised Traffic in Great Britain in 2006

This Working Paper presents the results of tests of various transport policies which could potentially have a major impact on private car travel and hence gain environmental benefits at a national level. The forecasting methodology was to take OPCS population forecasts for year 2006 in 28 age/sex/area type categories, predict the car available percentage of person in each category in 2006, and then predict trip mileage growth (by three mode types for the 28 categories each subdivided into car available and car non-availahle. For the latter two predications, NTS data for 1985/6 and 1991/3 were compared and projected forward with various adjustments. The effect of individual transport policies on trip rates for individual cells was determined from results derived from other studies, coupled with a consideration of economic theory. Of the tests considered, only the tripling of fuel prices for private mode transport was ahle to hold private mode mileage in 2006 at ahout its 1992 level

Travel Time Monitoring in Urban Areas – Survey Design.

This paper describes the design of a survey to measure variations in travel time and their possible causes and to develop cost effective travel time survey instruments. After describing the background and objectives of the study it reviews in turn the uses to which travel time data can be put and the resulting survey requirements, the factors which might cause variations in travel time, and the available survey methods. The survey strategy outlined in the final section is based on these reviews. It concentrates on inbound peak period travel times over five radial routes in Leeds, and uses number plate matching to measure inter-vehicle variation, and moving vehicle observer methods to measure inter-period variation. Two other methods are also employed. The surveyperiod is spread over 14 months to identify seasonal effects, but uses a Latin Square design to reduce the scale of the data collection task

Statistics of extinction and survival in Lotka-Volterra systems

We analyze purely competitive many-species Lotka-Volterra systems with random interaction matrices, focusing the attention on statistical properties of their asymptotic states. Generic features of the evolution are outlined from a semiquantitative analysis of the phase-space structure, and extensive numerical simulations are performed to study the statistics of the extinctions. We find that the number of surviving species depends strongly on the statistical properties of the interaction matrix, and that the probability of survival is weakly correlated to specific initial conditions.Comment: Previous version had error in authors. 11 pages, including 5 figure

The Development of a Common Investment Appraisal for Urban Transport Projects.

In December 1990 we were invited by Birmingham City Council and Centro to submit a proposal for an introductory study of the development of a common investment appraisal for urban transport projects. Many of the issues had arisen during the Birmingham Integrated Transport Study (BITS) in which we were involved, and in the subsequent assessment of light rail schemes of which we have considerable experience. In subsequent discussion, the objectives were identified as being:- (i) to identify, briefly, the weaknesses with existing appraisal techniques; (ii) to develop proposals for common methods for the social cost-benefit appraisal of both urban road and rail schemes which overcome these weaknesses; (iii) to develop complementary and consistent proposals for common methods of financial appraisal of such projects; (iv) to develop proposals for variants of the methods in (ii) and (iii) which are appropriate to schemes of differing complexity and cost; (v) to consider briefly methods of treating externalities, and performance against other public sector goals, which are consistent with those developed under (ii) to (iv) above; (vi) to recommend work to be done in the second phase of the study (beyond March 1991) on the provision of input to such evaluation methods from strategic and mode-specific models, and on the testing of the proposed evaluation methods. Such issues are particularly topical at present, and we have been able to draw, in our study, on experience of:- (i) evaluation methods developed for BITS and subsequent integrated transport studies (MVA) (ii) evaluation of individual light rail and heavy rail investment projects (ITS,MVA); (iii) the recommendations of AMA in "Changing Gear" (iv) advice to IPPR on appraisal methodology (ITS); (v) submissions to the House of Commons enquiry into "Roads for the Future" (ITS); (vi) advice to the National Audit Office (ITS) (vii) involvement in the SACTRA study of urban road appraisal (MVA, ITS

Randomly Amplified Polymorphic DNA Analysis Of Seagrass Halophila Ovalis.

Seagrasses are an important component of coastal system, not only important as nursery ground and shelter for many species of marine life, but also have great value in stabilizing and protecting coastlines from erosion due to the physical character of their leaves and root-rhizome system (Sudara et al. 1992

Quasiparticle spectrum of d-wave superconductors in the mixed state: a large Fermi-velocity anisotropy study

The quasiparticle spectrum of a two-dimensional d-wave superconductor in the mixed state, H_c1 << H << H_c2, is studied for large values of the ``anisotropy ratio'' alpha_D = v_F/v_Delta. For a square vortex lattice rotated by 45 degrees from the quasiparticle anisotropy axes (and the usual choice of Franz--Tesanovic singular gauge transformation) we determine essential features of the band structure asymptotically for large alpha_D, using an effective one-dimensional model, and compare them to numerical calculations. We find that several features of the band structure decay to zero exponentially fast for large alpha_D. Using a different choice of singular gauge transformation, we obtain a different band structure, but still find qualitative agreement between the 1D and full 2D calculations. Finally, we distort the square lattice into a non-Bravais lattice. Both the one- and two-dimensional numerical calculations of the energy spectra show a gap around zero-energy, with our gauge choice, and the two excitation spectra agree reasonably well.Comment: 14 pages, 13 figures, revte

Formality theorems for Hochschild complexes and their applications

We give a popular introduction to formality theorems for Hochschild complexes and their applications. We review some of the recent results and prove that the truncated Hochschild cochain complex of a polynomial algebra is non-formal.Comment: Submitted to proceedings of Poisson 200