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Gerald L Ullman - One of the best experts on this subject based on the ideXlab platform.
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Design of Construction Work Zones on High-Speed Highways
NCHRP Report, 2007Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This report explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. The contractor's final report on the research activities used to develop this report has been published as NCHRP Web Document 105. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers. This report will be of particular interest to practitioners responsible for the design of Construction Work zones.
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Final Report for NCHRP Report 581: Design of Construction Work Zones on High-Speed Highways
2006Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This document is the contractor's final report on the research activities used to develop NCHRP Report 581, "Design of Construction Work Zones on High-Speed Highways." NCHRP Report 581 explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers.
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Placement guidance for temporary concrete barriers in Construction Work zones : Developed with roadside safety analysis
Transportation Research Record, 2006Co-Authors: Richard J. Porter, Kevin M. Mahoney, Gerald L UllmanAbstract:An important design decision in Construction Work zones concerns the use and placement of temporary barriers. The temporary concrete safety shaped barrier is the option preferred by most state transportation agencies. No consensus on specific warrants or nationally recognized guidance exists. Of 32 state departments of transportation responding to a recent survey, 24 ranked having or improving Work zone guidance on "traffic barriers and roadside design" as "most important/critical." The objective of this paper is to investigate and evaluate the information, tools, and procedures available to aid individual designers and agencies in developing guidance for the use of traffic barriers in Construction Work zones. Principles of roadside barrier use for permanent roadways will be covered. Also covered will be benefit-cost analysis and adaptation of permanent roadway procedures and programs, specifically the Roadside Safety Analysis Program (RSAP), for the purpose of developing Work zone barrier guidance. Resul...
Richard J. Porter - One of the best experts on this subject based on the ideXlab platform.
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Artificial Neural NetWork Speed Profile Model for Construction Work Zones on High-Speed Highways
Journal of Transportation Engineering-asce, 2007Co-Authors: Douglas R Taylor, Kevin M. Mahoney, Bohdan T. Kulakowski, Saravanan Muthiah, Richard J. PorterAbstract:Speed profile models can be used as a diagnostic tool by highway engineers. Previous Work has investigated relationships between operating speed and geometric roadway elements for permanent roadway conditions on predominantly two-lane rural roads. However, little research of this type has been directed specifically toward Construction Work zones. In this study, a speed profile model for Construction Work zones on high speed highways was developed using artificial neural netWorks and made available for use by practitioners through a MS EXCEL interface. The model inputs include horizontal and vertical alignment variables, cross section dimensions and traffic control features. A linear reference system is used for model input and output. Three categories of vehicles—cars, trucks, and all vehicles—were used in this study. Models for the 15th percentile speed, mean speed, and 85th percentile speed were developed.
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Design of Construction Work Zones on High-Speed Highways
NCHRP Report, 2007Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This report explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. The contractor's final report on the research activities used to develop this report has been published as NCHRP Web Document 105. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers. This report will be of particular interest to practitioners responsible for the design of Construction Work zones.
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Final Report for NCHRP Report 581: Design of Construction Work Zones on High-Speed Highways
2006Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This document is the contractor's final report on the research activities used to develop NCHRP Report 581, "Design of Construction Work Zones on High-Speed Highways." NCHRP Report 581 explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers.
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Placement guidance for temporary concrete barriers in Construction Work zones : Developed with roadside safety analysis
Transportation Research Record, 2006Co-Authors: Richard J. Porter, Kevin M. Mahoney, Gerald L UllmanAbstract:An important design decision in Construction Work zones concerns the use and placement of temporary barriers. The temporary concrete safety shaped barrier is the option preferred by most state transportation agencies. No consensus on specific warrants or nationally recognized guidance exists. Of 32 state departments of transportation responding to a recent survey, 24 ranked having or improving Work zone guidance on "traffic barriers and roadside design" as "most important/critical." The objective of this paper is to investigate and evaluate the information, tools, and procedures available to aid individual designers and agencies in developing guidance for the use of traffic barriers in Construction Work zones. Principles of roadside barrier use for permanent roadways will be covered. Also covered will be benefit-cost analysis and adaptation of permanent roadway procedures and programs, specifically the Roadside Safety Analysis Program (RSAP), for the purpose of developing Work zone barrier guidance. Resul...
Kevin M. Mahoney - One of the best experts on this subject based on the ideXlab platform.
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Artificial Neural NetWork Speed Profile Model for Construction Work Zones on High-Speed Highways
Journal of Transportation Engineering-asce, 2007Co-Authors: Douglas R Taylor, Kevin M. Mahoney, Bohdan T. Kulakowski, Saravanan Muthiah, Richard J. PorterAbstract:Speed profile models can be used as a diagnostic tool by highway engineers. Previous Work has investigated relationships between operating speed and geometric roadway elements for permanent roadway conditions on predominantly two-lane rural roads. However, little research of this type has been directed specifically toward Construction Work zones. In this study, a speed profile model for Construction Work zones on high speed highways was developed using artificial neural netWorks and made available for use by practitioners through a MS EXCEL interface. The model inputs include horizontal and vertical alignment variables, cross section dimensions and traffic control features. A linear reference system is used for model input and output. Three categories of vehicles—cars, trucks, and all vehicles—were used in this study. Models for the 15th percentile speed, mean speed, and 85th percentile speed were developed.
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Design of Construction Work Zones on High-Speed Highways
NCHRP Report, 2007Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This report explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. The contractor's final report on the research activities used to develop this report has been published as NCHRP Web Document 105. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers. This report will be of particular interest to practitioners responsible for the design of Construction Work zones.
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Final Report for NCHRP Report 581: Design of Construction Work Zones on High-Speed Highways
2006Co-Authors: Kevin M. Mahoney, Richard J. Porter, Bohdan T. Kulakowski, Douglas R Taylor, Gerald L UllmanAbstract:This document is the contractor's final report on the research activities used to develop NCHRP Report 581, "Design of Construction Work Zones on High-Speed Highways." NCHRP Report 581 explores an approach for the selection of an appropriate Construction Work zone type; offers suggested guidance for the design of geometric features, including horizontal and vertical alignment, cross-sectional features, and barrier placement; and examines a variety of ancillary features such as drainage systems, lighting, and surface type. As part of the research associated with this activity, a Work zone prediction model and user's guide were created to help estimate free-flow vehicle speeds through two types of Construction Work zones on four lane freeways--single lane closures and median crossovers.
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Placement guidance for temporary concrete barriers in Construction Work zones : Developed with roadside safety analysis
Transportation Research Record, 2006Co-Authors: Richard J. Porter, Kevin M. Mahoney, Gerald L UllmanAbstract:An important design decision in Construction Work zones concerns the use and placement of temporary barriers. The temporary concrete safety shaped barrier is the option preferred by most state transportation agencies. No consensus on specific warrants or nationally recognized guidance exists. Of 32 state departments of transportation responding to a recent survey, 24 ranked having or improving Work zone guidance on "traffic barriers and roadside design" as "most important/critical." The objective of this paper is to investigate and evaluate the information, tools, and procedures available to aid individual designers and agencies in developing guidance for the use of traffic barriers in Construction Work zones. Principles of roadside barrier use for permanent roadways will be covered. Also covered will be benefit-cost analysis and adaptation of permanent roadway procedures and programs, specifically the Roadside Safety Analysis Program (RSAP), for the purpose of developing Work zone barrier guidance. Resul...
Paul Chinowsky - One of the best experts on this subject based on the ideXlab platform.
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Safety risk interactions among highway Construction Work tasks
Construction Management and Economics, 2011Co-Authors: Matthew R Hallowell, Behzad Esmaeili, Paul ChinowskyAbstract:Recent research has produced frameWorks for integrating safety risk data into project schedules, visual models and other Construction planning tools. Unfortunately, only a few studies have attempted to quantify base-level safety risk for Construction tasks and no study has attempted to quantify the degree to which spatial and temporal interactions among tasks contribute to the potential for injury. A research study was performed to quantify the impact that pair-wise spatial and temporal interactions have on the base-level risk of 25 common highway Construction Work tasks in the United States. Six hundred risk interactions were quantified by obtaining and aggregating over 23 500 individual ratings from certified experts using the Delphi method. The results indicate that incompatible tasks may increase the base-level risk up to 60%. The most incompatible highway Construction tasks are: (1) installing curbs and gutters and installing rigid pavement; and (2) Construction zone traffic control and installing rigid pavement. Additionally, watering and dust palliatives and pavement marking is the one compatible task pair and there are 45 neutral task pairs. The resulting database and analysis have the potential to increase the efficacy of existing frameWorks for integration of safety risk data with project planning tools.
Martin Skitmore - One of the best experts on this subject based on the ideXlab platform.
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Pricing Construction Work: a marketing viewpoint
Construction Management and Economics, 2007Co-Authors: Martin Skitmore, Hedley SmythAbstract:Recent Work on pricing has shown that neoclassical microeconomic theory (NCMT) is preferred to tendering theory and that implied by absorption, or full‐cost, pricing of Construction Work because of its explicit treatment of market conditions, competitor behaviour and firm capacity levels. Applying NCMT in practice, however, requires the consideration of pricing from a marketing perspective. This paper examines the challenges involved in terms of the two prevalent marketing paradigms—marketing mix and relationship marketing—to pricing Construction Work generally, and the traditional contracting (TC), design and Construction (D&C) and speculative building (SB) procurement systems in particular. In general, the marketing mix (MM) approach, having the closest fit with NCMT, is most aligned to current practice. However, conceptual and practical limitations are identified. Relationship marketing (RM) is theoretically more applicable, yet has been largely overlooked in practice due to the transaction costs and i...
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The effect of client and type and size of Construction Work on a contractor's bidding strategy
2001Co-Authors: Derek S. Drew, Martin SkitmoreAbstract:This paper offers a bidding strategy model for use by contractors as part of a more informed approach in selecting which contracts to bid for, and as a basis for determining the most appropriate mark-up level for various types and sizes of Construction Work and client types. Regression analysis is used in measuring a contractor’s competitiveness between bids (by using the lowest bid / own bid ratio) and within bids (by using the lowest bid / cost estimate ratio) according to type and size of Construction Work and client type. The model was tested on a large and reputable Hong Kong contractor. This particular contractor's bidding behaviour was found to be largely unaffected by type of Construction Work but significantly affected by client type and size of Construction Work. Three quadratic models (regressing lowest bid / cost estimate on size of Construction Work) are also successfully developed for projects from the private sector, the Hong Kong Government and the Hong Kong Housing Authority respectively.
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The effect of client and type and size of Construction Work on a contractor's bidding strategy
Building and Environment, 2001Co-Authors: Derek S. Drew, Martin SkitmoreAbstract:Abstract This paper offers a bidding strategy model for use by contractors as part of a more informed approach in selecting which contracts to bid for, and as a basis for determining the most appropriate mark-up level for various types and sizes of Construction Work and client types. Regression analysis is used in measuring a contractor’s competitiveness between bids (by using the lowest bid/own bid ratio) and within bids (by using the lowest bid/cost estimate ratio) according to type and size of Construction Work and client type. The model was tested on a large and reputable Hong Kong contractor. This particular contractor’s bidding behaviour was found to be largely unaffected by the type of Construction Work, but significantly affected by the client type and the size of the Construction Work. Three quadratic models (regressing lowest bid/cost estimate on the size of the Construction Work) are also successfully developed for projects from the private sector, the Hong Kong Government and the Hong Kong Housing Authority, respectively.