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Grant G Schultz - One of the best experts on this subject based on the ideXlab platform.
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Safety Analysis of Access Management Implementation in Utah
2011Co-Authors: Grant G SchultzAbstract:Access Management, defined in the Transportation Research Board Access Management Manual as “the systematic control of the location, spacing, design, and operation of driveways, median openings, interchanges, and street connections to a roadway,” has been shown to have a positive impact on roadway safety. Numerous studies have been conducted on the safety relationship of Access Management techniques as a function of Access spacing, corner clearance, and medians. Several of these studies have been conducted in the United States, including studies completed in the state of Utah. The results of research performed at Brigham Young University for the Utah Department of Transportation are highlighted in this paper. Specific research includes raised median safety impacts from both a traditional analysis methodology and using Bayesian methods, as well as an analysis of Access Management techniques (e.g., corner clearance, Access spacing, median openings, left-turn lanes, etc.) at major-arterial intersections. The purpose of the paper is to present an overview on the safety impacts of Access Management identified, while providing the necessary references to allow the reader to review details and specific analysis results of these and other safety studies. The results of the analyses indicate that Access Management techniques play a role in improving and maintaining safety along urban and suburban arterials and at major-arterial intersections in the state of Utah. Access Management has improved, and will continue to improve, safety when implemented appropriately. Agencies across the world should identify how Access Management can best be implemented in their jurisdictions and apply these principles.
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Prioritizing Access Management Implementation
Transportation Research Record, 2009Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. Safety and performance on those roads are continual concerns. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proved successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit from Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop a performance index-based prioritization process to target arterial roads that would benefit from the implementation of Access Management techniques. Using the results of the research, decision makers can better determine which sections of roadway may benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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Prioritizing Access Management Implementation
2008Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. As such the safety and performance of these roads is a continual concern. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proven successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit by the implementation of Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop the prioritization process based on principles of performance indices that can be utilized to target arterial roads that would benefit from Access Management techniques and principles. Utilizing the results of the research, decision makers can better determine which sections of roadway can benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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Safety Impacts of Access Management Techniques in Utah
Transportation Research Record, 2007Co-Authors: Grant G Schultz, Jeffrey Lewis, Tim BoschertAbstract:Traffic volumes and congestion across Utah have continued to increase in recent years, particularly on arterial streets. This increased traffic volume has amplified the emphasis on implementing Access Management techniques (i.e., raised medians or driveway consolidation) to alleviate some of the safety concerns associated with Access on arterial streets. To determine the safety benefits provided by Access Management techniques in Utah, an evaluation of the safety performance of arterials in which Access Management techniques have been implemented within the state was performed. To complete the evaluation, a unique, yet proven, tool available through the Utah Department of Transportation was used. This tool is a geographic information system-enabled, web-delivered data almanac that allows researchers to establish specific filters that can be used to sort crash data, identifying high crash locations and establishing crash trends. Several locations where Access Management techniques have been implemented in ...
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A Prioritization Process for Access Management Implementation in Utah
2007Co-Authors: Grant G Schultz, Kordel T BraleyAbstract:Appropriate Access Management techniques can improve the safety and efficiency of arterial roads. To determine which roads can most benefit by the implementation of Access Management techniques, a prioritization process was developed to recommend various Access Management treatments. To serve as the basis for the performance index, a database was created including identifying features, characteristics, and crash history for 175 arterial road segments on Utah state routes. Stepwise linear regression was applied to the data collected to determine which characteristics of the roads were correlated with crash rate, crash severity, and specific collision types. Recommendations for Access Management treatments were given in the form of a decision tree to classify existing or future road segments into subcategories based on volume, signal spacing, land use, and other criteria, with recommendations provided for each subcategory.
Tim Boschert - One of the best experts on this subject based on the ideXlab platform.
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Prioritizing Access Management Implementation
Transportation Research Record, 2009Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. Safety and performance on those roads are continual concerns. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proved successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit from Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop a performance index-based prioritization process to target arterial roads that would benefit from the implementation of Access Management techniques. Using the results of the research, decision makers can better determine which sections of roadway may benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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Prioritizing Access Management Implementation
2008Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. As such the safety and performance of these roads is a continual concern. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proven successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit by the implementation of Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop the prioritization process based on principles of performance indices that can be utilized to target arterial roads that would benefit from Access Management techniques and principles. Utilizing the results of the research, decision makers can better determine which sections of roadway can benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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Safety Impacts of Access Management Techniques in Utah
Transportation Research Record, 2007Co-Authors: Grant G Schultz, Jeffrey Lewis, Tim BoschertAbstract:Traffic volumes and congestion across Utah have continued to increase in recent years, particularly on arterial streets. This increased traffic volume has amplified the emphasis on implementing Access Management techniques (i.e., raised medians or driveway consolidation) to alleviate some of the safety concerns associated with Access on arterial streets. To determine the safety benefits provided by Access Management techniques in Utah, an evaluation of the safety performance of arterials in which Access Management techniques have been implemented within the state was performed. To complete the evaluation, a unique, yet proven, tool available through the Utah Department of Transportation was used. This tool is a geographic information system-enabled, web-delivered data almanac that allows researchers to establish specific filters that can be used to sort crash data, identifying high crash locations and establishing crash trends. Several locations where Access Management techniques have been implemented in ...
William L Eisele - One of the best experts on this subject based on the ideXlab platform.
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Evaluating the Michigan Access Management Program: Findings and Lessons Learned
Transportation Research Record, 2011Co-Authors: William L Eisele, William E Frawley, Tom DoyleAbstract:As state departments of transportation (DOTs) and local transportation agencies make difficult funding decisions in these financially constrained times, Access Management improvements provide a cost-effective alternative for improving the safety and operation of roadways. Mindful of the benefits of implementing Access Management treatments, the Michigan DOT has conducted an Access Management program since 2002. The Michigan DOT contracted with the Texas Transportation Institute (TTI) to provide recommendations for adjustments to the Michigan Access Management program. As a result of the evaluation, TTI identified lessons learned related to the importance of (a) continuing support and funding for the Access Management program, (b) a clear Access Management policy statement, (c) coordination and cooperation between state and local transportation agencies, (d) continued training, (e) interagency coordination across state DOT divisions, (f) continued review and update of technical documentation and guidance, ...
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Access Management Outreach Materials: Promoting Access Management Benefits in Texas
2008Co-Authors: William L Eisele, William E FrawleyAbstract:The benefits of Access Management treatments are well documented. Since 1996, the Texas Department of Transportation (TxDOT) has funded numerous studies to facilitate the study of the benefits of Access Management treatments as a design element to improve roadway safety and operations. Researchers at the Texas Transportation Institute have performed much of this research for TxDOT. In Texas, Access Management treatments have proven effective in balancing the need for roadway movement on arterial streets, while providing necessary Access to residential and commercial developments. This paper highlights the history of Access Management program development in Texas. The paper also highlights recently-developed outreach materials that can be used to promote the implementation of Access Management treatments in Texas and other states. The paper describes the need for the outreach materials, the outreach materials themselves, and implementation and promotion of the outreach materials. Concluding remarks are provided at the end of the paper.
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Recommended Access Management Guidelines for Texas
2006Co-Authors: William L Eisele, William E FrawleyAbstract:This report documents the research performed during this two-year research project to provide recommendations for the use of Access Management techniques on state roadways in Texas. In the first year of the project, the research team focused on developing a matrix of guidelines for the application of different Access Management techniques for various roadway Access classifications. The Access Management treatments for which recommended guidelines are presented include Access spacing, corner clearance, median treatments, auxiliary lanes, alternate left-turn treatments, Access separation at interchanges, frontage roads, and the use of traffic impact analyses for site development. The matrix allows the user to identify critical threshold criteria for the application of each Access Management technique for each roadway Access classification. In the second year of the project, the matrix has been revised. The revised matrix and supporting information is presented in this document. The guidelines presented in this report will be valuable for state transportation professionals for use on new and retrofit projects as a toolbox of techniques for managing Access to all state roadways―thus preserving the intended use of these facilities.
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ESTIMATING THE IMPACTS OF Access Management TECHNIQUES: FINAL RESULTS
2004Co-Authors: William L Eisele, William E Frawley, C M ToycenAbstract:This research report summarizes the research activities and findings of the 2.5-year research project to investigate the impacts of Access Management treatments. The first objective of the project was to estimate the impacts of Access Management techniques through field data collection at selected sites in Texas and to perform simulation of traffic performance. Findings related to travel time and delay from three case studies are provided in this report. Theoretical corridors were also created and analyzed to provide further insight into corridor performance with changes in median type, driveway density, and traffic volume. The researchers identify key considerations for using microsimulation (VISSIM) for investigating Access Management treatments. Generally, the research identified a range of differences in travel time (and relatively small changes in speed) when comparing a corridor with a two-way left-turn lane (TWLTL) with the installation of a raised median along the three case study corridors and three theoretical corridors. The reduction in the number of conflict points along the corridors with Access Management was large (up to 60% for the case studies and up to 75% for the theoretical corridors). The reduction in conflict points illustrates the potential safety impacts of Access Management. The second objective of the research was to estimate the safety benefits of Access Management treatments by investigating crash data from select corridors where Access Management treatments have been installed. A key part of this analysis is the assessment of the crash information used in the analysis. The research identified a relationship between increasing Access point density and increasing crash rates. It also identified a reduction in crashes when comparing corridors with a TWLTL with those with a raised median. Crash severity was also reduced with the raised median.
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IMPLEMENTING A PROGRAM FOR Access Management IN TEXAS: LESSONS LEARNED
2003Co-Authors: William E Frawley, William L EiseleAbstract:The Texas Department of Transportation recently sponsored research through the Texas Transportation Institute to provide recommendations for implementing a comprehensive Access Management program in the State. The research includes a provision to produce an "Access Management Guidebook for Texas" for use by planners and engineers when planning, designing, and reviewing highway projects and Access requests. This paper describes some of the lessons learned in the research related to Access classification, Access spacing criteria, median alternatives, and the overall implementation of the program. Specifically, in terms of Access classification, considerations include what type of Access classification system is necessary to develop a successful program. For Access spacing and median alternatives, lessons learned were related to what unsignalized Access (driveway) spacing criteria and median opening guidelines are most applicable for adoption in Texas and why. Lastly, in terms of the lessons learned in the overall implementation of the program, several questions have been raised throughout the development of the program that have led to localized changes to the program that have strengthened the program overall. This paper presents the results of these and other lessons learned, describes the background of Access Management, and outlines selected alternatives used in existing Access Management programs in other states. Finally, the presentation provides the current status of the comprehensive Access Management program in Texas. The research and experiences that have emerged as a result of this project are expected to be useful to engineers and planners not only within Texas, but also in other states that are developing or modifying comprehensive Access Management programs.
William E Frawley - One of the best experts on this subject based on the ideXlab platform.
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Evaluating the Michigan Access Management Program: Findings and Lessons Learned
Transportation Research Record, 2011Co-Authors: William L Eisele, William E Frawley, Tom DoyleAbstract:As state departments of transportation (DOTs) and local transportation agencies make difficult funding decisions in these financially constrained times, Access Management improvements provide a cost-effective alternative for improving the safety and operation of roadways. Mindful of the benefits of implementing Access Management treatments, the Michigan DOT has conducted an Access Management program since 2002. The Michigan DOT contracted with the Texas Transportation Institute (TTI) to provide recommendations for adjustments to the Michigan Access Management program. As a result of the evaluation, TTI identified lessons learned related to the importance of (a) continuing support and funding for the Access Management program, (b) a clear Access Management policy statement, (c) coordination and cooperation between state and local transportation agencies, (d) continued training, (e) interagency coordination across state DOT divisions, (f) continued review and update of technical documentation and guidance, ...
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Access Management Outreach Materials: Promoting Access Management Benefits in Texas
2008Co-Authors: William L Eisele, William E FrawleyAbstract:The benefits of Access Management treatments are well documented. Since 1996, the Texas Department of Transportation (TxDOT) has funded numerous studies to facilitate the study of the benefits of Access Management treatments as a design element to improve roadway safety and operations. Researchers at the Texas Transportation Institute have performed much of this research for TxDOT. In Texas, Access Management treatments have proven effective in balancing the need for roadway movement on arterial streets, while providing necessary Access to residential and commercial developments. This paper highlights the history of Access Management program development in Texas. The paper also highlights recently-developed outreach materials that can be used to promote the implementation of Access Management treatments in Texas and other states. The paper describes the need for the outreach materials, the outreach materials themselves, and implementation and promotion of the outreach materials. Concluding remarks are provided at the end of the paper.
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Recommended Access Management Guidelines for Texas
2006Co-Authors: William L Eisele, William E FrawleyAbstract:This report documents the research performed during this two-year research project to provide recommendations for the use of Access Management techniques on state roadways in Texas. In the first year of the project, the research team focused on developing a matrix of guidelines for the application of different Access Management techniques for various roadway Access classifications. The Access Management treatments for which recommended guidelines are presented include Access spacing, corner clearance, median treatments, auxiliary lanes, alternate left-turn treatments, Access separation at interchanges, frontage roads, and the use of traffic impact analyses for site development. The matrix allows the user to identify critical threshold criteria for the application of each Access Management technique for each roadway Access classification. In the second year of the project, the matrix has been revised. The revised matrix and supporting information is presented in this document. The guidelines presented in this report will be valuable for state transportation professionals for use on new and retrofit projects as a toolbox of techniques for managing Access to all state roadways―thus preserving the intended use of these facilities.
-
ESTIMATING THE IMPACTS OF Access Management TECHNIQUES: FINAL RESULTS
2004Co-Authors: William L Eisele, William E Frawley, C M ToycenAbstract:This research report summarizes the research activities and findings of the 2.5-year research project to investigate the impacts of Access Management treatments. The first objective of the project was to estimate the impacts of Access Management techniques through field data collection at selected sites in Texas and to perform simulation of traffic performance. Findings related to travel time and delay from three case studies are provided in this report. Theoretical corridors were also created and analyzed to provide further insight into corridor performance with changes in median type, driveway density, and traffic volume. The researchers identify key considerations for using microsimulation (VISSIM) for investigating Access Management treatments. Generally, the research identified a range of differences in travel time (and relatively small changes in speed) when comparing a corridor with a two-way left-turn lane (TWLTL) with the installation of a raised median along the three case study corridors and three theoretical corridors. The reduction in the number of conflict points along the corridors with Access Management was large (up to 60% for the case studies and up to 75% for the theoretical corridors). The reduction in conflict points illustrates the potential safety impacts of Access Management. The second objective of the research was to estimate the safety benefits of Access Management treatments by investigating crash data from select corridors where Access Management treatments have been installed. A key part of this analysis is the assessment of the crash information used in the analysis. The research identified a relationship between increasing Access point density and increasing crash rates. It also identified a reduction in crashes when comparing corridors with a TWLTL with those with a raised median. Crash severity was also reduced with the raised median.
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IMPLEMENTING A PROGRAM FOR Access Management IN TEXAS: LESSONS LEARNED
2003Co-Authors: William E Frawley, William L EiseleAbstract:The Texas Department of Transportation recently sponsored research through the Texas Transportation Institute to provide recommendations for implementing a comprehensive Access Management program in the State. The research includes a provision to produce an "Access Management Guidebook for Texas" for use by planners and engineers when planning, designing, and reviewing highway projects and Access requests. This paper describes some of the lessons learned in the research related to Access classification, Access spacing criteria, median alternatives, and the overall implementation of the program. Specifically, in terms of Access classification, considerations include what type of Access classification system is necessary to develop a successful program. For Access spacing and median alternatives, lessons learned were related to what unsignalized Access (driveway) spacing criteria and median opening guidelines are most applicable for adoption in Texas and why. Lastly, in terms of the lessons learned in the overall implementation of the program, several questions have been raised throughout the development of the program that have led to localized changes to the program that have strengthened the program overall. This paper presents the results of these and other lessons learned, describes the background of Access Management, and outlines selected alternatives used in existing Access Management programs in other states. Finally, the presentation provides the current status of the comprehensive Access Management program in Texas. The research and experiences that have emerged as a result of this project are expected to be useful to engineers and planners not only within Texas, but also in other states that are developing or modifying comprehensive Access Management programs.
Kordel T Braley - One of the best experts on this subject based on the ideXlab platform.
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Prioritizing Access Management Implementation
Transportation Research Record, 2009Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. Safety and performance on those roads are continual concerns. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proved successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit from Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop a performance index-based prioritization process to target arterial roads that would benefit from the implementation of Access Management techniques. Using the results of the research, decision makers can better determine which sections of roadway may benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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Prioritizing Access Management Implementation
2008Co-Authors: Grant G Schultz, Kordel T Braley, Tim BoschertAbstract:Traffic volumes and congestion continue to increase on arterial roads. As such the safety and performance of these roads is a continual concern. Transportation systems must be evaluated on an ongoing basis to ensure that people and goods can be moved as efficiently and safely as possible. Safety and performance indices provide a method to numerically measure given data about a system so that comparisons and rankings on safety and performance can be made as objectively as possible. One of the sets of tools that have proven successful in improving the safety and efficiency of arterial roads are Access Management techniques. To determine which roads can most benefit by the implementation of Access Management techniques, a prioritization process was developed to guide decision makers in the implementation process. Recommendations were given in the form of a decision tree classifying existing or future road segments into subcategories based on volume, signal spacing, adjacent land use, and other criteria. The objective of this paper is to document the steps followed to develop the prioritization process based on principles of performance indices that can be utilized to target arterial roads that would benefit from Access Management techniques and principles. Utilizing the results of the research, decision makers can better determine which sections of roadway can benefit from controlling driveway Access, installing raised medians, providing future planning, or looking to a solution other than Access Management.
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A Prioritization Process for Access Management Implementation in Utah
2007Co-Authors: Grant G Schultz, Kordel T BraleyAbstract:Appropriate Access Management techniques can improve the safety and efficiency of arterial roads. To determine which roads can most benefit by the implementation of Access Management techniques, a prioritization process was developed to recommend various Access Management treatments. To serve as the basis for the performance index, a database was created including identifying features, characteristics, and crash history for 175 arterial road segments on Utah state routes. Stepwise linear regression was applied to the data collected to determine which characteristics of the roads were correlated with crash rate, crash severity, and specific collision types. Recommendations for Access Management treatments were given in the form of a decision tree to classify existing or future road segments into subcategories based on volume, signal spacing, land use, and other criteria, with recommendations provided for each subcategory.
