1,720,971 research outputs found
Road traffic pollution monitoring and modelling tools and the UK national air quality strategy.
Full text linkThis paper provides an assessment of the tools required to fulfil the air quality management role now expected of local authorities within the UK. The use of a range of pollution monitoring tools in assessing air quality is discussed and illustrated with evidence from a number of previous studies of urban background and roadside pollution monitoring in Leicester. A number of approaches to pollution modelling currently available for deployment are examined. Subsequently, the modelling and monitoring tools are assessed against the requirements of Local Authorities establishing Air Quality Management Areas. Whilst the paper examines UK based policy, the study is of wider international interest
Towards an understanding of adaptive cruise control
No full textAdaptive cruise control (ACC) provides assistance to the driver in the task of longitudinal control of their vehicle during motorway driving. The system controls the accelerator, engine powertrain and vehicle brakes to maintain a desired time-gap to the vehicle ahead. This research describes the results of a detailed microscopic simulation investigation into the potential impacts of ACC on motorway driving. In addition to simulation, real vehicle driving profiles, obtained from instrumented vehicle experiments in three European countries, have been used to compare real following behaviour with that of a simulated ACC equipped vehicle. This new approach has shown that following with an ACC system can provide considerable reductions in the variation of acceleration compared to manual driving. This indicates a potential comfort gain for the driver and environmental benefits. A number of critical situations in which ACC does not perform well have also been identified. The research also highlights the limitations of microscopic simulation in modelling the impacts of ACC because of the lack of understanding of the interaction between the driver and the ACC system relative to the traffic conditions
A comparative assessment of driving behaviours at three sites
Full text linkMany Intelligent Transport Systems (ITS) that are now under intensive investigation have been designed or assessed with a particular target consumer group in mind. In order for these (and many other) systems to be successfully used around the globe however, some appreciation will be necessary of how behaviours, and hence uses and impacts, may change between different sites and between different countries.
This article reports on an instrumented vehicle study designed to assess differences in Motorway driving behaviour between three sites, one in the U.K., one in France and one in Germany. Substantial differences were found between typical car-following headways and time to collisions observed at the sites. The experiment also confirmed that many people drive well below the current recommended safe following distances.
It has not been possible through this study to determine why the differences exist between the sites, nor whether they are country specific. However, the findings are important in establishing that significant differences do exist. These differences could impact on the effectiveness of roadside telematics systems as well as for the design of in-vehicle Advanced Vehicle Control and Safety Systems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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