Road safety: Research and reality 6th Reuben Smeed memorial lecture

Research has had a major influence in advancing road safety in Britain over more than 60 years. Lessons learnt in the early years provide a model for effective conduct of research of high quality to aid and influence practice and policy making. As the control of road safety research has become more widespread over the last decade and effort more diffused, problems have arisen which militate against the appropriateness and successful application of findings. Conflicts between researchers, practitioners and policy makers stem from lack of mutual understanding of their roles, the need to balance scientific rigour against the urgency of government and practice, and inadequate coherent communication.The potential for road casualty reduction in Britain has been addressed at intervals since the early 1960s. Assessment of the latest trends in casualties, set against current activities to achieve target reductions, shows the need for a further update to redefine priorities. For future advancement of road safety, a 20-point plan of activities is suggested. Technical, social, economic and institutional difficulties, of varying degrees, will need to be overcome to achieve the objectives of the plan. Most importantly, the academic and professional standing of road safety workers needs to be raised.     

Carbon flux in ice–ocean–plankton systems of the Bellingshausen Sea during a period of ice retreat

Most analyses of marine microbial systems in the seasonally ice covered areas of the Southern Ocean have been based on data from the major embayment areas of the Ross and Weddell Seas. In this study data were collected at stations covering a range of regimes from full ice cover through to open water in the Bellingshausen Sea. A major feature of the production system was a rapid retreat of the ice-edge, which uncoupled the marginal ice zone from a phytoplankton bloom which remained associated with a frontal system. This bloom was maintained, and probably initiated, in an unusual environment generated by the interaction between the marginal ice zone and the front. Size-based analyses of the microbial system were derived for ice-covered, recently ice-covered and open water sites. Estimates of standing stocks and key rate processes were combined to produce a single food web network for each station. The under-ice system was one of low production and low recycling but apparently high retention. As the ice retreated the microbial systems to the north began to develop, but these were constrained by grazing pressure. The bloom in the area appeared to be sustained even though estimated losses were far higher than production, although the high sedimentation losses expected were not observed. The carbon flow networks are discussed in relation to the environmental changes and the interaction of the marginal ice zone and the frontal system appears crucial to the phytoplankton. Microzooplankton grazing is implicated as a major controlling factor. The local microbial dynamics are strongly influenced by material which was produced at an earlier time and somewhere else in the Southern Ocean.     

Estimating the demand for electric automobiles using fully disaggregated probabilistic choice analysis

This study uses probabilistic choice models to predict potential demand for electric cars. Survey data are employed to estimate separate utility functions for each of 51 subjects. This provides a sample distribution of consumer preferences for vehicle attributes including price, operating cost and range. The results indicate great diversity in individual trade-offs among attributes, with range and top speed generally being highly valued. The sample of utility functions is then used to predict potential market shares for various kinds of electric vehicles as second cars. Demand is quite limited, except when (a) electric cars are considerably more advanced than anything likely to be available in the near future, and (b) consumers fear massive gasoline shortages. The latter effect derives from an observed “bias” in favor of electric autos, which is plausibly interpreted as a hedge against disruptions in the gasoline market.     

The evolution of Canadian liner shipping policy

This paper traces the evolution of Canadian liner shipping policy from its beginnings, at the time of the initial formation of shipping conferences, in the late nineteenth century, to its current form, as provided by the 1987 Shipping Conference Exemption Act. It is shown that evolution has been associated with a shift in policy orientation from an initial British-based position to a contemporary form that is distincly American in nature. The reasons for this shift are analysed and the similarities and differences between curent Canadian and U.S.A. legislation are identified. The paper shows that the adoption by Canada of an American-style policy became inevitable once the container revolution had physically integrated the transport systems of both nations.     

Numerical experiments on the prediction of sea surface temperature anomalies in the Gulf of Mexico

The conservation of thermal energy equation applied to the mixed layer of the ocean, has been used to predict the sea surface temperature anomalies (SSTA) and the month-to-month changes in the Gulf of Mexico. The model includes the horizontal transport of heat by mean ocean currents and by turbulent eddies, as well as the heating by short and long wave radiation, evaporation and sensible heat given off to the atmosphere. A comparative study is carried out on the relative importance of the heating and transport terms. An objective verification of the skill of the predictions is presented for each season and for the whole period from March 1986 to February 1987. The predictions using only the heating terms have some skill over the control predictions (persistence and return to normal). The skill is substantially increased when the horizontal transport of heat by turbulent mixing is included in the model. The incorporation in the model of the Ekman wind drift current anomalies computed from the anomalous surface geostrophic wind improves appreciably the skill of the predictions in winter and fall.The mixed layer depth computed using the Kraus and Turner theory with dissipation, shows that the depths in summer and fall are shallower than in spring and winter. The effect of the shallow mixed layer depth in the model becomes apparent in summer and fall, improving the skill of the predictions in these seasons, with respect to the skill obtained using a constant mixed layer depth of 60 m.The incorporation in the model of the cooling in the mixed layer by turbulent entrainment of colder water from the thermocline, does not improve in an appreciable way the average skill of the predictions.     

Geography and the cruise ship port selection process

The cruise ship industry is currently undergoing a period of rapid expansion. New cruise capacity threatens to produce overtonnaging, with future berths exceeding demand. Despite this development, cruise operators are confident that a growing North American market will be able to satisfy the equilibrium condition sought by vessel operators. This research explores where the new tonnage might be deployed and its eventual impact on the cruise industry. Geographic concepts are utilized to test and support the premise that geography contributes positively to the cruise port selection process. Itineraries, influenced by 'site' and 'situation,' are presently still the most important factor affecting cruise port selection.     

Review of the State of Development of Advanced Vehicle Control Systems (AVCS)

This paper provides a broad review of the developments that have taken place within the past thirty years in the field now known as Advanced Vehicle Control Systems (AVCS). This long time horizon was chosen to ensure that significant findings from earlier generations of work are not overlooked today. Following a history of the international development of AVCS, several methods of classifying AVCS are introduced. The main body of the paper reviews the relevant literature in lateral, longitudinal and integrated control of road vehicles and summarizes the most significant findings from this work.     

Effects of Model Complexity on the Performance of Automated Vehicle Steering Controllers: Model Development, Validation and Comparison

Recent research on autonomous highway vehicles has begun to focus on lateral control strategies. The initial work has focused on vehicle control during low-g maneuvers at constant vehicle speed, typical of lane merging and normal highway driving. In this paper, and its companion paper, to follow, the lateral control of vehicles during high-g emergency maneuvers is addressed. Models of the vehicle dynamics are developed, showing the accuracy of the different models under low and high-g conditions. Specifically, body roll, tire and drive-train dynamics, tire force saturation, and tire side force lag are shown to be important effects to include in models for emergency maneuvers. Current controllers, designed for low-g maneuvers only, neglect these effects. The follow on paper demonstrates the performance of lateral controllers during high-g lateral emergency maneuvers using these vehicle models.