105,294 research outputs found
Signal control using vehicle localization probe data
No full textThis paper presents a simulation test bed and methodology for evaluating urban signalized junction control algorithms that use localization probe data from all vehicles in the local area. The simulator is based on SIAS Paramics micro-simulation software with bespoke software modules built on top for automatic network generation, localization data processing and signal control. Localization algorithms tested use a hierarchical structure of auctioning agents. Early tests of control algorithms on an isolated signalized junction indicate performance that compares favourably with the MOVA algorithm using inductive loop data.<br/
The use of simulation in the design of a road transport incident detection algorithm
No full textAutomatic incident detection is becoming one of the core tools of urban traffic management, enabling more rapid identification and response to traffic incidents and congestion. Existing traffic detection infrastructure within urban areas (often installed for traffic signal optimization) provides urban traffic control systems with a near continuous stream of data on the state of traffic within the network. The creation of a simulation to replicate such a data stream therefore provides a facility for the development of accurate congestion detection and warning algorithms. This paper describes firstly the augmentation of a commercial traffic model to provide an urban traffic control simulation platform and secondly the development of a new incident detection system (RAID-Remote Automatic Incident Detection), with the facility to use the simulation platform as an integral part of the design and calibration process. A brief description of a practical implementation of RAID is included along with summary evaluation results
Making in-class skills training more effective: the scope for interactive videos to complement the delivery of practical pedestrian training
No full textSkills and awareness of young pedestrians can be improved with on-street practical pedestrian training, often delivered in schools in the United Kingdom by local authorities with the intention of improving road safety. This training is often supplemented by in-class paper based worksheet activities which are seen to be less effective than practical training in that they focus on knowledge acquisition rather than directly improving the correct application of safe pedestrian skills at the roadside. Previous research indicates that interactive video tools have the potential to develop procedural skills whilst offering an engaging road safety educational experience, which could positively impact on road crossing behaviour.In this paper, the design and development of a hazard-identification interactive road safety training video targeting child road crossing skills is presented. The interactive video was shown to be an engaging training resource for 6-7 year old children. The tool’s scope for improving pedestrians’ roadside skills is considered along with the wider implications for interactive video to aid safety training in other areas
A methodology for traffic state estimation and signal control utilizing high wireless device penetration
No full textThis paper presents a methodology for fusing data from multiple sensors, including wireless devices, to make an estimation of the state of an urban traffic network. An extended Kalman filter is employed along with a state evolution model to make estimates of the state in a discretized network. Results are presented from simulation tests of signal controllers on a network with three signalized junctions. Two signal control methods are tested: SCOOT and a machine learning junction control algorithm that employs the discretized state structure described in this paper. These tests represent lower and upper performance benchmarks and present a significant difference. The tests also demonstrate a framework for the future evaluation of the proposed methodology
The evolution of urban traffic control: changing policy and technology
No full textThe history of urban traffic control (UTC) throughout the past century has been a continued race to keep pace with ever more complex policy objectives and consistently increasing vehicle demand. Many benefits can be observed from an efficient urban traffic control system, such as reduced congestion, increased economic efficiency and improved road safety and air quality.There have been significant advances in vehicle detection and communications technologies which have enabled a series of step changes in the capabilities of UTC systems, from early (fixed time) signal plans to modern integrated systems. A variety of UTC systems have been implemented throughout the world, each with individual strengths and weaknesses; this paper seeks to compare the leading commercial systems (and some less well known systems) to highlight the key characteristics and differences before assessing whether the current UTC systems are capable of meeting modern transport policy obligations and desires.This paper then moves on to consider current and future transport policy and the technological landscape in which UTC will need to operate over the coming decades, where technological advancements are expected to move UTC from an era of limited data availability to an era of data abundance.<br/
Detecting shockwaves on motorways from inductive loops: A microscopic simulation based analysis
No full textGerman energy market fallout from the Japanese earthquake
No full textThe German response to the Fukushima nuclear power plant incident was possibly the most significant change of policy towards nuclear power outside Japan, leading to a sudden and very significant shift in the underlying power generation structure in Germany. This provides a very useful natural experiment on the impact of changing proportions of conventional fuel inputs to power production, helping us to see how changed proportions in future as a result of policy moves are likely to impact. We find through use of a conventional demand- supply framework that despite the swift, significant change, the main impact was a relatively modest increase in prices occasioned by a shift of the supply curve; there were no appreciable quantity effects on the market, such as power outages, despite some views that the impacts would be significant
Simulation of turbulent flow, heat and mass transfer using a residual-distribution approach
No full textApplied Science
Recent Decisions
No full textComments on recent decisions by Robert R. Waterson, Hugh E. Wall, Francis W. Matthys, Granville P. Ziegler, Thomas H. Nelson, Stanley A. Rosenstein, and John M. Doyle
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