Twenty First Century Transportation System Solutions - a New Type of Small, Relatively Tall and Narrow Active Tilting Commuter Vehicle

There are many problems that face transportation systems as the twenty-first century approaches, and many solutions will be required. Mass transportation systems are one large area of research that will provide some solutions. This paper presents another possible solution at the other end of the spectrum, small relatively tall and narrow tilting commuter vehicles for individual transportation. A historical overview of the various types of tilting vehicles built or proposed over the last forty years is shown and the results of these studies are discussed. If one considers a relatively tall and narrow vehicle, (under 1.0 meters or 40“ wide), to maintain high speed performance in cornering it becomes necessary to bank the vehicle into a corner to prevent overturning. The design of a modem active tilting suspension and control law for a small narrow, one-half width, commuter vehicles is presented. Analysis of the static and dynamic tipping limits illustrates which vehicles are considered tall and narrow requiring active tilting. The performance of such vehicles as they enter a steady corner is considered and how tilt dynamics may feel to passengers is discussed.     

Incomplete cost – incomplete benefit analysis in transport appraisal

This paper examines the current application of transport appraisal in the UK, in particular exploring the partiality of cost–benefit analysis (CBA) within the wider multi-criteria analysis (MCA) process. It argues that applying a quantitative assessment of the varied impacts of complex transport projects can only be partial within the CBA. Analysis can overlook social, human life, environmental and built environment impacts, and projects can be inconsistent with the planning strategy for an area. The application of CBA is critically reviewed using two case studies: the proposed upgrade of the South Fylde railway line and the Heysham-M6 Link Road, both from North West England. A participatory MCA process is suggested to help improve the process of transport appraisal, as part of an improved public debate on transport investment priorities.     

A dense water outflow from the Ross Sea, Antarctica: Mixing and the contribution of tides

We use hydrographic, current, and microstructure measurements, and tide-forced ocean models, to estimate benthic and interfacial mixing impacting the evolution of a bottom-trapped outflow of dense shelf water from the Drygalski Trough in the northwestern Ross Sea. During summer 2003 an energetic outflow was observed from the outer shelf ( 500 m isobath) to the  1600 m isobath on the continental slope. Outflow thickness was as great as  200 m, and mean speeds were  0.6 m s^− 1 relative to background currents exceeding  1 m s^− 1 that were primarily tidal in origin. No outflow was detected on the slope in winter 2004, although a thin layer of dense shelf water was present on the outer shelf. When the outflow was well-developed, the estimated benthic stress was of order one Pascal and the bulk Froude number over the upper slope exceeded one. Diapycnal scalar diffusivity (K_z) values in the transition region at the top of the outflow, estimated from Thorpe-scale analysis of potential density and measurements of microscale temperature gradient from sensors attached to the CTD rosette, were of order 10^− 3−10^− 2 m² s^− 1. For two cases where the upper outflow boundary was particularly sharply defined, entrainment rate w_e was estimated from K_z and bulk outflow parameters to be  10^− 3 m s^− 1 ( 100 m day^− 1). A tide-forced, three-dimensional primitive equation ocean model with Mellor-Yamada level 2.5 turbulence closure scheme for diapycnal mixing yields results consistent with a significant tidal role in mixing associated with benthic stress and shear within the stratified ocean interior.     

Credible commitment and congestion pricing

Transportation analysts frequently assert that congestion pricing’s political obstacles can be overcome through astute use of the toll revenue pricing generates. Such “revenue recycling,” however, implies that the collectors of the toll revenue will not be its final recipients, meaning that any revenue recipient must believe that the revenue collector will honor promises to deliver the money. This raises the potential for credible commitment problems. Promises to spend revenue can solve one political problem, because revenue is an easy benefit to understand, but create another one, because revenue is easy to divert. Revenue recycling may therefore not be a promising way to build political support for congestion pricing. We highlight the role commitment problems have played efforts to implement congestion pricing, using examples from around the world and then focusing on California. Because congestion reduction is a more certain benefit than any particular use of the toll revenue, demonstration projects, rather than revenue promises, will be key to pricing’s political success.     

Measuring the potential for automobile fuel savings in the US: The impact of obesity

High rates of oil consumption and obesity in the US have become important socioeconomic concerns. While these concerns may seem unrelated at first, growing obesity rates in the US increase fuel consumption by adding passenger weight to vehicles. This paper estimates the additional amount of fuel (i.e., gasoline) consumed annually by noncommercial passenger highway vehicles in the US due to passenger overweight and obesity. The mathematical model presented in this paper estimates that as many as one billion additional gallons of gasoline are consumed each year due to overweight and obesity in the US, accounting for up to 0.8% of the fuel consumed by these vehicles annually. This additional fuel consumption causes carbon dioxide emissions of up to 20 billion pounds or more, accounting for up to 0.5% of the annual carbon dioxide emissions in the transportation sector.     

Tidal current variability in the Central Great Barrier Reef

With tidal data from the literature and the field, a two-dimensional (depth-averaged) numerical model was formulated to simulate the dominant semi-diurnal tidal hydrodynamics of the Central Great Barrier Reef continental shelf. Importantly, the individual mesh dimensions of the numerical scheme were set at approximately 2 × 2 km which was sufficient resolution to incorporate the topography of each reef within the matrix. The model provided a new detailed understanding of the influence of the reef matrix on the tidal currents of the outer shelf. In particular, the model demonstrated that the spatial variability in the tidal current's speed and direction exists down to the scale of the 2 km grid size. The model also demonstrated the significant tidally-induced residual currents that result from the interaction with the complex topography of the reef matrix. The advective effect of these tidal currents would be significant as the tidally-induced residual currents are of similar magnitude to the non-tidal currents of the region. Further, the spatial variability in the modelled and observed tidal currents suggests highly spatially variable advective processes operate within the reef waters.     

A utility-based bicycle speed choice model with time and energy factors

Transportation - This paper presents a utility-based behavioral model of bicycle speed choice. A mathematical framework is developed with travel time, energy expenditure, and control factors....