Cargo tank roll stability study: final report

Rollovers are among the most serious crashes of cargo tank motor vehicles carrying hazardous materials. They are more likely to be fatal to the driver of the vehicle than other crashes, and they can cause spills and necessitate highway closures. The Federal Motor Carrier Safety Administration (FMCSA) has identified the need to study cargo tanks, from design through operation, to improve their roll stability. The objective of this program was to evaluate four complementary approaches to reducing the incidence of cargo tank truck rollovers: improving the training of drivers, deploying electronic stability aids, implementing new vehicle designs, and learning lessons from highway designs. The benefits, in terms of reduced numbers of rollover crashes, that could accrue from each approach, have been estimated, along with the costs of achieving those benefits. All four approaches are expected to be cost beneficial. Ultimate responsibility for the safety of the vehicle rests with the driver. The driver must be aware of the situations that can lead to rollover and have the skills and vigilance to prevent those situations from developing. Drowsiness and inattention together contribute to 1 in 5 cargo tank rollovers, so adherence to viable and legal schedules of work and rest is essential. Modern, motion-base simulators can help new drivers acquire skills more quickly and without consuming fuel, so simulators can pay for themselves through reduced training costs alone, for those carriers large enough to afford them. Electronic stability aids automatically slow a vehicle when it starts to round a corner too fast. Excessive cornering speed accounts for about 1 in 5 cargo tank rollovers, and these devices can be quite effective in what they do while adding only marginally to the cost of a tractor or trailer. Vehicles with more stable designs are available on the market today. Lowering the trailer’s center of gravity by only three inches can reduce rollover incidence by more than 10 percent. However, these trailers have been slow to gain market share because they have a cost premium and their benefit is not widely appreciated. Improvements in highway geometry, surface, or signage, of course, have to be considered at individual sites.Federal Motor Carrier Safety Administration, Washington, D.C.http://deepblue.lib.umich.edu/bitstream/2027.42/64890/1/102503.pd

Incorporating Air Transport Congestion into a Computable General Equilibrium Model of the US Economy

Air transport, like all transport sectors, has a strong relationship with national-economic performance. Consequently, investments that produce large changes in the availability of air transportation will have impacts on overall economic growth. This relationship makes an economy-wide framework relevant for evaluating the aggregate and cross-industry impacts of air transport policy and large-scale investment. One such investment is the Next Generation Air Transportation System (NextGen) initiative of the U.S. Federal Aviation Administration (FAA). In part, NextGen is intended to reduce the growth of congestion as the consumption of air transportation continues to increase in the future. Computable General Equilibrium (CGE) models describe an economy by linking supply and demand for all commodities and include macroeconomic relationships. This paper describes an interdisciplinary approach for modifying the U.S. Applied General Equilibrium (USAGE) model to reflect air transportation congestion through decreasing returns to scale (DRTS), and characterizes the consequence this modification has on modeled economy-wide NextGen impact