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901.
This paper provides a framework for assessing the progress that is being made in the computer-assisted dispatching of trains. The state of the art is described in general terms, and future research needs are identified. 相似文献
902.
903.
This paper looks at the relationships between ship size, handling rate and ship berth time for five major ports in the United Kingdom. The results show that there is no simple linear relationship between these variables. The causes and implications of this are discussed. 相似文献
904.
905.
This article presents the economic rationale for road pricing and provides some scale on the magnitude of peak period tolls that might be justified. It discusses the impacts of such tolls on congestion, air quality and economic development and suggests a long term strategy towards areawide implementation of peak period pricing. It discusses current trends which are increasing the likelihood for implementation of congestion pricing and toll roads in the future. In particular, it discusses some aspects of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) which will eliminate some of the current restraints on congestion pricing and toll highways.Abbreviations ETC
Electronic toll collection
- FHWA
Federal Highway Administration
- HOV
High occupancy vehicle
- ISTEA
Intermodal Surface Transportation Efficiency Act
- LOS
Level of service
- TCM
Transportation control measure
- V/C
Volume-to-capacity ratio
- VMT
Vehicle mile(s) of travel
- vphpl
Vehicles per hour per lane 相似文献
906.
907.
R. C. Redfield D. C. Karnopp 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1988,17(5):231-253
Most vehicle suspension systems use fixed passive components that offer a compromise in performance between sprung mass isolation, suspension travel, and tireroad contact force. Recently, systems with discretely adjustable dampers and air springs been added to production vehicles. Active and semi-active damping concepts for vehicle suspensions have also been studied theoretically and with physical prototypes. This paper examines the optimal performance comparisons of variable component suspensions, including active damping and full-state feedback, for “quartercar” heave models. Two and three dimensional optimizations are computed using performance indicators to find the component parameters (control gains) that provide “optimal” performance for statistically described roadway inputs. The effects of performance weighting and feedback configuration are examined. Active damping is shown to be mainly important for vehicle isolation. A passive vehicle suspension can control suspension travel and tire contact force nearly as well as a full state feedback control strategy. 相似文献
908.
A major research study funded by the UK Overseas Development Administration (ODA) and designed to establish the necessary considerations for viability of mass rapid transit railways in developing cities was recently completed. The analytical core of the study was a pre-appraisal model, which combines an innovative strategic land use/transport model utilizing relationships from developing cities and an economic evaluation model. This model — MRTAP — has now been developed into a user-friendly package which the ODA intend should be made widely available in the developing world. The paper describes the basis of this model. 相似文献
909.
The purpose of this study is to examine the spatial and temporal characteristics of weekend work episodes. Specifically, we
examine whether individuals work over the weekend and, if they work, whether they work at home or outside the home. We also
model the time of day of weekend work. The empirical analysis in the paper is based on the 2000 San Francisco Bay Area Travel
Survey. The results indicate the important effects of day of week/seasonal effects, individual demographics, work-related
variables, household characteristics, and location variables on weekend work participation characteristics. The models estimated
in the paper may be embedded within a larger weekend activity-travel pattern forecasting model system. 相似文献
910.
B.M. Broderick R.T. ODonoghue 《Transportation Research Part D: Transport and Environment》2007,12(8):537-547
The CALINE4 model is widely used to predict the effect of vehicle emissions on ambient concentrations close to roadways. It requires an evaluation of the rate at which different air pollutants are emitted by vehicles, taking into account things such as vehicle flow, velocity, type and age. For Europe the databases of the COmputer Program to calculate Emissions from Road Transport (COPERT) are combined with local vehicle details to obtain site-specific emission factors for dispersion modelling. The ability of CALINE4 to predict the spatial variation of hydrocarbon concentrations downwind of a motorway is assessed, as is the accuracy of COPERT III composite emission factors for several hydrocarbon compounds. The concentrations of seven traffic-associated compounds is found at three locations downwind and upwind of a motorway. Modelled and measured background-corrected downwind concentrations are compared on three bases: daily peak hour concentrations, mean concentrations, and a set of model evaluation parameters. 相似文献