The Experts below are selected from a list of 2295 Experts worldwide ranked by ideXlab platform
Chris J. Fornal - One of the best experts on this subject based on the ideXlab platform.
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Methodology for Evaluating Effectiveness of Traffic-Responsive Systems on Intersection Congestion and Traffic Safety
Transportation Research Record, 1997Co-Authors: Rashad M Hanbali, Chris J. FornalAbstract:In 1986, the city of Milwaukee applied for and received approval for a Hazard Elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection complex had several approaches at or above capacity, associated long queues of traffic, and an annual traffic-accident rate of more than three per 1 million entering vehicles. The Hazard Elimination grant called for the installation of a closed-loop, traffic-responsive signal system to manage the congestion and to reduce traffic accidents. The intersection complex presented many constraints on traffic-responsive operation, the most critical of which was that the three arterials formed a signal triangle (three separate signalized intersections) with intersection spacing as short as 27.4m (90 ft). FHWA realized the unusual nature of this project and designated it an experimental project in 1987. The development of the traffic-responsive signal system within the man...
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Methodology for Evaluating Effectiveness of Traffic-Responsive Systems on Intersection Congestion and Traffic Safety
Transportation Research Record: Journal of the Transportation Research Board, 1997Co-Authors: Rashad M Hanbali, Chris J. FornalAbstract:In 1986, the city of Milwaukee applied for and received approval for a Hazard Elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection complex had several approaches at or above capacity, associated long queues of traffic, and an annual traffic-accident rate of more than three per 1 million entering vehicles. The Hazard Elimination grant called for the installation of a closed-loop, traffic-responsive signal system to manage the congestion and to reduce traffic accidents. The intersection complex presented many constraints on traffic-responsive operation, the most critical of which was that the three arterials formed a signal triangle (three separate signalized intersections) with intersection spacing as short as 27.4m (90 ft). FHWA realized the unusual nature of this project and designated it an experimental project in 1987. The development of the traffic-responsive signal system within the many constraints of the location is described. After a lengthy process, the traffic-responsive system became operational in September 1993 and proved to be an operational success by reducing the length of traffic queues. After extensive data collection, an analysis and evaluation confirmed that the traffic-responsive signal system reduced the occupancy levels per vehicle on the system detectors and reduced the incidence of congestion-related traffic accidents.
Sabyasachee Mishra - One of the best experts on this subject based on the ideXlab platform.
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Economic Competitiveness and Equity-Based Safety Improvement Allocation Model for Urban Intersections
2014Co-Authors: Sabyasachee Mishra, Sushant Sharma, Mihalis M. Golias, Stephen D. BoylesAbstract:Economic competitiveness and equity can be two competing objectives while allocating funds for implementation of safety alternatives on urban intersections. One of the critical phase of current safety management process (Hazard Elimination program) undertaken by most states is resource allocation among identified crash locations. Literature underlines the importance of this phase and lack of sophisticated tools available to state planning agencies for evaluating federal and state policies. The study overcomes this limitation by proposing an optimization based resource allocation model that maximizes safety benefits, subjected to budget and policy constraints. The proposed model incorporates economic competitiveness in the allocation and distributes improvements to urban intersections such that maximum economical benefits are obtained from crash savings. However, results show that while economic competitiveness leads to optimal benefits, resource allocation is inequitable. Hence equity based models are developed by adding two policy options: equity in opportunity and equity in outcome. The resource allocation model is solved using sequential quadratic programming. The model is applied to crash prone intersections in four counties of southeast Michigan. The proposed model is generic and scalable, with flexibility in including policy options often considered by state and local agencies.
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Optimal Investment Decision-Making Strategies for Safety Improvements on Urban Intersections
2014Co-Authors: Sabyasachee Mishra, Sushant Sharma, Mihalis M. Golias, Stephen D. BoylesAbstract:Urban intersections crashes cause significant economic loss among all roadways. The safety management and investment process undertaken by most states in the United States is referred as Hazard Elimination program, and consists of three standardized steps i.e. (i) identification of critical crash locations, (ii) development of countermeasures and (iii) resource allocation among identified crash locations. Often these three steps are independent with limited detail of each step at the state planning agencies. Literature review underlines the importance of third step and lack of sophisticated tools available to state planning agencies for leveraging information obtained from first two steps. Further, non-strategic fund allocation and unavailability of methods for evaluating strategies leads to sub-optimal fund allocation. This paper overcomes these limitations and proposes multiple optimal resource allocation strategies for improvements at urban intersections that maximize safety benefits, under budget and policy constraints. Policy measures based on benefits maximization (economic competitiveness), priority to locations with higher severity of crashes (relative urgency), equitable allocation (equity), and pure dominance (multiple alternatives at one location) produces significantly different alternative and fund allocation for investment. The model is applied to selected intersections in four counties of southeast Michigan. Results from model application reinforce pragmatic consideration of developed strategies/policies and tools for investment/resource allocation of highway safety projects on critical urban intersections.
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A synchronized model for crash prediction and resource allocation to prioritize highway safety improvement projects
Procedia - Social and Behavioral Sciences, 2013Co-Authors: Sabyasachee MishraAbstract:Urban intersections are key locations of traffic crashes that contribute significantly to the economic losses. Safety management process undertaken by most states in the United States (U.S), is often referred to as the Hazard Elimination program which consists of three steps: (1) selections of Hazardous locations, (candidate locations) where safety improvements are warranted, (2) development of countermeasures for potential reduction of crashes, (3) allocation of resources among the independent candidate locations in conformance to budgetary and other constraints. Often these three steps are independently considered with very limited detail on each step in the state planning agencies. This paper presents a simultaneous model which predicts the occurrence of crashes and allocates resources by maximizing benefits subjected to budget and other constraints. The analysis is carried out for a planning period of five years. The crash prediction is analysed as a negative binomial model. The resource allocation model is solved using branch and bound algorithm. Prediction and allocation is conducted simultaneously to achieve realistic results rather than analysing both steps independently. The allocation model further prioritizes the projects to be implemented to optimally distribute funds to maximize benefits. Model results reveal that the proposed approach can be used as a tool for resource allocation on highway safety projects for urban intersections.
Rashad M Hanbali - One of the best experts on this subject based on the ideXlab platform.
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Methodology for Evaluating Effectiveness of Traffic-Responsive Systems on Intersection Congestion and Traffic Safety
Transportation Research Record, 1997Co-Authors: Rashad M Hanbali, Chris J. FornalAbstract:In 1986, the city of Milwaukee applied for and received approval for a Hazard Elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection complex had several approaches at or above capacity, associated long queues of traffic, and an annual traffic-accident rate of more than three per 1 million entering vehicles. The Hazard Elimination grant called for the installation of a closed-loop, traffic-responsive signal system to manage the congestion and to reduce traffic accidents. The intersection complex presented many constraints on traffic-responsive operation, the most critical of which was that the three arterials formed a signal triangle (three separate signalized intersections) with intersection spacing as short as 27.4m (90 ft). FHWA realized the unusual nature of this project and designated it an experimental project in 1987. The development of the traffic-responsive signal system within the man...
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Methodology for Evaluating Effectiveness of Traffic-Responsive Systems on Intersection Congestion and Traffic Safety
Transportation Research Record: Journal of the Transportation Research Board, 1997Co-Authors: Rashad M Hanbali, Chris J. FornalAbstract:In 1986, the city of Milwaukee applied for and received approval for a Hazard Elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection complex had several approaches at or above capacity, associated long queues of traffic, and an annual traffic-accident rate of more than three per 1 million entering vehicles. The Hazard Elimination grant called for the installation of a closed-loop, traffic-responsive signal system to manage the congestion and to reduce traffic accidents. The intersection complex presented many constraints on traffic-responsive operation, the most critical of which was that the three arterials formed a signal triangle (three separate signalized intersections) with intersection spacing as short as 27.4m (90 ft). FHWA realized the unusual nature of this project and designated it an experimental project in 1987. The development of the traffic-responsive signal system within the many constraints of the location is described. After a lengthy process, the traffic-responsive system became operational in September 1993 and proved to be an operational success by reducing the length of traffic queues. After extensive data collection, an analysis and evaluation confirmed that the traffic-responsive signal system reduced the occupancy levels per vehicle on the system detectors and reduced the incidence of congestion-related traffic accidents.
Stephen D. Boyles - One of the best experts on this subject based on the ideXlab platform.
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Economic Competitiveness and Equity-Based Safety Improvement Allocation Model for Urban Intersections
2014Co-Authors: Sabyasachee Mishra, Sushant Sharma, Mihalis M. Golias, Stephen D. BoylesAbstract:Economic competitiveness and equity can be two competing objectives while allocating funds for implementation of safety alternatives on urban intersections. One of the critical phase of current safety management process (Hazard Elimination program) undertaken by most states is resource allocation among identified crash locations. Literature underlines the importance of this phase and lack of sophisticated tools available to state planning agencies for evaluating federal and state policies. The study overcomes this limitation by proposing an optimization based resource allocation model that maximizes safety benefits, subjected to budget and policy constraints. The proposed model incorporates economic competitiveness in the allocation and distributes improvements to urban intersections such that maximum economical benefits are obtained from crash savings. However, results show that while economic competitiveness leads to optimal benefits, resource allocation is inequitable. Hence equity based models are developed by adding two policy options: equity in opportunity and equity in outcome. The resource allocation model is solved using sequential quadratic programming. The model is applied to crash prone intersections in four counties of southeast Michigan. The proposed model is generic and scalable, with flexibility in including policy options often considered by state and local agencies.
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Optimal Investment Decision-Making Strategies for Safety Improvements on Urban Intersections
2014Co-Authors: Sabyasachee Mishra, Sushant Sharma, Mihalis M. Golias, Stephen D. BoylesAbstract:Urban intersections crashes cause significant economic loss among all roadways. The safety management and investment process undertaken by most states in the United States is referred as Hazard Elimination program, and consists of three standardized steps i.e. (i) identification of critical crash locations, (ii) development of countermeasures and (iii) resource allocation among identified crash locations. Often these three steps are independent with limited detail of each step at the state planning agencies. Literature review underlines the importance of third step and lack of sophisticated tools available to state planning agencies for leveraging information obtained from first two steps. Further, non-strategic fund allocation and unavailability of methods for evaluating strategies leads to sub-optimal fund allocation. This paper overcomes these limitations and proposes multiple optimal resource allocation strategies for improvements at urban intersections that maximize safety benefits, under budget and policy constraints. Policy measures based on benefits maximization (economic competitiveness), priority to locations with higher severity of crashes (relative urgency), equitable allocation (equity), and pure dominance (multiple alternatives at one location) produces significantly different alternative and fund allocation for investment. The model is applied to selected intersections in four counties of southeast Michigan. Results from model application reinforce pragmatic consideration of developed strategies/policies and tools for investment/resource allocation of highway safety projects on critical urban intersections.
L Lavagno - One of the best experts on this subject based on the ideXlab platform.
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Linear programming for Hazard Elimination in asynchronous circuits
Journal of VLSI signal processing systems for signal image and video technology, 1994Co-Authors: L Lavagno, N. Shenoy, Alberto Sangiovanni-vincentelliAbstract:Hazards can be globally eliminated from an asynchronous circuit synthesized from a Signal Transition Graph by repeatedly solving an appropriate Linear Program. This article describes how to analyze the STG specification and the synthesized circuit, using bounded delay information, to formulate the problem and use a branch-and-bound procedure to solve it. Known information about the environment delays can be expressed as time bounds on the external signal transitions, and it can be exploited by the proposed methodology.
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linear programming for optimum Hazard Elimination in asynchronous circuits
International Conference on Computer Design, 1992Co-Authors: L Lavagno, Alberto SangiovannivincentelliAbstract:It is shown that Hazards can be optimally eliminated from circuits synthesized starting with a signal transition graph (STG) specification. The proposed approach is based on a linear programming (or integer linear programming) formulation, and as such it can be solved efficiently and optimally for a variety of cost functions. Suggested cost functions optimize either the total padded delay, an estimate of the increase in area, or the maximum cycle time of the complete system. It is also shown that delay padding on all fanouts of STG signals is a necessary and sufficient condition for Hazard Elimination if the structure and delay of each combinational logic block cannot be changed. Experimental results indicate that the improvements obtained are well worth the added complexity of linear program solution. >
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ICCD - Linear programming for optimum Hazard Elimination in asynchronous circuits
Proceedings 1992 IEEE International Conference on Computer Design: VLSI in Computers & Processors, 1Co-Authors: L Lavagno, Alberto Sangiovanni-vincentelliAbstract:It is shown that Hazards can be optimally eliminated from circuits synthesized starting with a signal transition graph (STG) specification. The proposed approach is based on a linear programming (or integer linear programming) formulation, and as such it can be solved efficiently and optimally for a variety of cost functions. Suggested cost functions optimize either the total padded delay, an estimate of the increase in area, or the maximum cycle time of the complete system. It is also shown that delay padding on all fanouts of STG signals is a necessary and sufficient condition for Hazard Elimination if the structure and delay of each combinational logic block cannot be changed. Experimental results indicate that the improvements obtained are well worth the added complexity of linear program solution. >
