A Simulator Based Evaluation of Speed Reduction Measures for Rural Arterial Roads

In Great Britain accident rates on rural roads are not falling as fast as those on urban roads. In 1993 the number of casualties from accidents on rural A roads was 4% higher than the average for 1981-85, which is the baseline for the Department of Transport target of a one third reduction in road accident casualties by the year 2000. Driving too fast for the conditions is a major factor in accident causation. High speeds in conjunction with the varying geometric conditions common on rural single-carriageway A roads, result in a fatal accident rate which is higher than that for any other type of road. The aim of the research was to investigate, in a safe and controlled manner using the University of Leeds Advanced Driving Simulator, the effectiveness of a variety of measures for reducing driver speeds on rural single-carriageway arterial roads, in order to identify practical and cost-effective combinations of treatments to reduce both the frequency and severity of accidents on such roads. Treatments appropriate to each of three situations were investigated. These were: (1) treatments that reduce speed and speed variance on fairly straight roads (general treatments); (2) treatments that reduce curve entry speeds for sharp bends; (3) treatments that reduce speeds on the approach to and through villages. Treatments investigated included the use of road markings to reduce lane width or produce horizontal deflection; the use of signs both on posts and on the road surface; and the use of optical illusions to affect the driver's perception of speed or road width. Many of the treatments have been used previously, but few have been evaluated in a controlled way. The first phase of the research involved the evaluation of each individual treatment. The treatments were evaluated with respect to their effect on speed, vehicle lateral position, and incidence of overtaking. The second phase of the research involved the evaluation of variations on and combinations of the most effective treatments. Substantial reductions in speeds were obtained by some of the treatments evaluated, for all three situations studied. There were also reductions in speed variance. These reductions are significant both in statistical and practical road safety terms. For the village situation the most effective combination of treatments was the chicane without hatching, yellow or white transverse lines throughout the village, and countdown speed limit signs on the approach to the village. For the bend treatments the most effective treatments were transverse lines with reducing spacing (including a central area filled with transverse lines); a central hatched area; a Wundt illusion (a series of chevrons with increasing angles but constant spacing, pointing towards the driver); and hatched areas at the edges of the road. Further speed reductions may be produced by combining one of the above treatments with the most effective sign treatments — SLOW or a triangular, warning sign style, advisory speed sign painted on the road surface. For the general treatments all those which involved lane narrowing produced speeds significantly different from the control. Shoulders delineated by continuous lines were more effective, than those delineated by broken lines. Shoulder width was not important, but carriageway width was. For central hatching, type of delineation and width of hatched area was not important. The location (central/edge) and type (removing carriageway or lane space) of the narrowing was not important

Reducing fuel consumption by using a new fuel-efficiency support tool

A fuel-efficiency support tool has been designed, which includes a normative model describing optimal driver behaviour for minimising fuel consumption. If actual behaviour deviates from optimal behaviour, the system presents advice on how to change behaviour. Evaluation revealed that drivers used ~16% less fuel compared with `normal driving

An Elastomeric Energy Storage System to Improve Vehicle Efficiency.

Most regenerative braking systems studied hitherto have made use of batteries, tlywheels and hydraulic accumulators. The present study has investigated the use of elastomers for such systems. The ability of elastomers to store large amounts of energy, together with the fact that this energy can be recovered quickly, makes them attractive materials for propulsion devices and inherently simple to engineer. Theoretical and experimental research has shown that the development of an elastomeric regenerative braking system does appear to be technically feasible. The predicted rubber characteristics have been compared with the known characteristics of a conventional engine. The results show that the tractive effort produced by the elastomer is capable of matching the characteristics of the engine considered in this work. Rates of input and output energy have also been calculated to determine the process of energy storage and retrieval throughout a typical driving cycle. The energy store appears to be capable of reproducing many stages of the three driving cycles considered. When there is insufticient energy in the system, power boosts from the conventional engine are required. In order to increase the overall savings achieved by the system, the engine was 'replaced' by one which had force (and therefore power) characteristics of one half of the conventional engine initially considered. It was found that the reduced power engine was sufficient to supply the extra power boosts as required. In addition to reduced engine and brake wear, fuel consumption and emissions have been shown to be drastically reduced. If these values could be achieved in practice, the benefits of such a system are immediately apparent. The potential financial savings available to the car user corresponding to the decrease in fuel consumption would provide a strong incentive. Environmentally the benefits are two fold, firstly the reduction in pollution emissions means cleaner air and has an impact on global warming, and secondly reduced fuel consumption means that fossil fuel reserves may last considerably longer than currently predicted thus reducing the immediate need for alternatives sources

The <i>Castalia</i> mission to Main Belt Comet 133P/Elst-Pizarro

We describe Castalia, a proposed mission to rendezvous with a Main Belt Comet (MBC), 133P/Elst-Pizarro. MBCs are a recently discovered population of apparently icy bodies within the main asteroid belt between Mars and Jupiter, which may represent the remnants of the population which supplied the early Earth with water. Castalia will perform the first exploration of this population by characterising 133P in detail, solving the puzzle of the MBC’s activity, and making the first in situ measurements of water in the asteroid belt. In many ways a successor to ESA’s highly successful Rosetta mission, Castalia will allow direct comparison between very different classes of comet, including measuring critical isotope ratios, plasma and dust properties. It will also feature the first radar system to visit a minor body, mapping the ice in the interior. Castalia was proposed, in slightly different versions, to the ESA M4 and M5 calls within the Cosmic Vision programme. We describe the science motivation for the mission, the measurements required to achieve the scientific goals, and the proposed instrument payload and spacecraft to achieve these

Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj

Nuclear shadowing is observed in the per-nucleon cross-sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj decreases, the size of the shadowing effect, as well as its A dependence, are found to approach the corresponding measurements in photoproduction.Comment: 22 pages, incl. 6 figures, to be published in Z. Phys.

A human ciliopathy reveals essential functions for NEK10 in airway mucociliary clearance

Mucociliary clearance, the physiological process by which mammalian conducting airways expel pathogens and unwanted surface materials from the respiratory tract, depends on the coordinated function of multiple specialized cell types, including basal stem cells, mucus-secreting goblet cells, motile ciliated cells, cystic fibrosis transmembrane conductance regulator (CFTR)-rich ionocytes, and immune cells1,2. Bronchiectasis, a syndrome of pathological airway dilation associated with impaired mucociliary clearance, may occur sporadically or as a consequence of Mendelian inheritance, for example in cystic fibrosis, primary ciliary dyskinesia (PCD), and select immunodeficiencies3. Previous studies have identified mutations that affect ciliary structure and nucleation in PCD4, but the regulation of mucociliary transport remains incompletely understood, and therapeutic targets for its modulation are lacking. Here we identify a bronchiectasis syndrome caused by mutations that inactivate NIMA-related kinase 10 (NEK10), a protein kinase with previously unknown in vivo functions in mammals. Genetically modified primary human airway cultures establish NEK10 as a ciliated-cell-specific kinase whose activity regulates the motile ciliary proteome to promote ciliary length and mucociliary transport but which is dispensable for normal ciliary number, radial structure, and beat frequency. Together, these data identify a novel and likely targetable signaling axis that controls motile ciliary function in humans and has potential implications for other respiratory disorders that are characterized by impaired mucociliary clearance

Combining Kohonen maps with Arima time series models to forecast traffic flow

A hybrid method of short-term traffic forecasting is introduced; the KARIMA method. The technique uses a Kohonen self-organizing map as an initial classifier; each class has an individually tuned ARIMA model associated with it. Using a Kohonen map which is hexagonal in layout eases the problem of defining the classes. The explicit separation of the tasks of classification and functional approximation greatly improves forecasting performance compared to either a single ARIMA model or a backpropagation neural network. The model is demonstrated by producing forecasts of traffic flow, at horizons of half an hour and an hour, for a French motorway. Performance is similar to that exhibited by other layered models, but the number of classes needed is much smaller (typically between two and four). Because the number of classes is small, it is concluded that the algorithm could be easily retrained in order to track long-term changes in traffic flow and should also prove to be readily transferrable