Search

Search Results

• 1. [Article] Building and Maintaining a Statewide Transportation Framework

  Creating and maintaining up-to-date sharable Geographic Information SystemsTransportation (GIS-T) data is challenging. Many states are working on Transportation Framework efforts to build a complete, consistent, ...

  Citation × Citation Citation Abstract Copy Title: Building and Maintaining a Statewide Transportation Framework Author: Dueker, Kenneth, Bender, Paul Year: 2002 Creating and maintaining up-to-date sharable Geographic Information SystemsTransportation (GIS-T) data is challenging. Many states are working on Transportation Framework efforts to build a complete, consistent, and current transportation data layer in conjunction with the NSDI and Geospatial One-Stop efforts. This paper summarizes an effort that systematically re-examined transportation data sharing issues as part of the development of a Transportation Framework for the State of Washington. Business needs were assessed in terms of spatial and temporal accuracy needs of stakeholders and users of a state-wide Transportation Framework. A conceptual model was developed for a Transportation Framework with emphasis on data flows to update and maintain it and other transportation databases. The paper concludes with a synthesis of issues, including determining the desired robustness of the Transportation Framework and cost allocation principles for possible add-on enhancements. Title: Building and Maintaining a Statewide Transportation Framework Author: Dueker, Kenneth, Bender, Paul Year: 2002 Creating and maintaining up-to-date sharable Geographic Information SystemsTransportation (GIS-T) data is challenging. Many states are working on Transportation Framework efforts to build a complete, consistent, and current transportation data layer in conjunction with the NSDI and Geospatial One-Stop efforts. This paper summarizes an effort that systematically re-examined transportation data sharing issues as part of the development of a Transportation Framework for the State of Washington. Business needs were assessed in terms of spatial and temporal accuracy needs of stakeholders and users of a state-wide Transportation Framework. A conceptual model was developed for a Transportation Framework with emphasis on data flows to update and maintain it and other transportation databases. The paper concludes with a synthesis of issues, including determining the desired robustness of the Transportation Framework and cost allocation principles for possible add-on enhancements. Close

• 2. [Article] Sharing Transportation GIS Data

  Updating and maintaining Geographic Information Systems-Transportation data (GIS-T data) is proving difficult. Different database formats needed to support diverse applications leads to inconsistencies ...

  Citation × Citation Citation Abstract Copy Title: Sharing Transportation GIS Data Author: Dueker, Kenneth, Bender, Paul, Zhang, Jihong Year: 2000 Updating and maintaining Geographic Information Systems-Transportation data (GIS-T data) is proving difficult. Different database formats needed to support diverse applications leads to inconsistencies and inaccuracies, and duplication in updating. Dueker and Butler (1998) have proposed an Enterprise GIS-T data model that unbundles the various components of transportation data (network links, cartography, and attributes) to facilitate generating application-specific networks, and which eases updating and maintenance. However, developers of existing application-specific databases that employ integrated data models that bundle the network link with cartography and attributes are reluctant to step back to an intermediate form for managing their data. Consequently, attention is given in this report to the development of a method of incorporating transportation system changes directly to existing application- specific networks. Title: Sharing Transportation GIS Data Author: Dueker, Kenneth, Bender, Paul, Zhang, Jihong Year: 2000 Updating and maintaining Geographic Information Systems-Transportation data (GIS-T data) is proving difficult. Different database formats needed to support diverse applications leads to inconsistencies and inaccuracies, and duplication in updating. Dueker and Butler (1998) have proposed an Enterprise GIS-T data model that unbundles the various components of transportation data (network links, cartography, and attributes) to facilitate generating application-specific networks, and which eases updating and maintenance. However, developers of existing application-specific databases that employ integrated data models that bundle the network link with cartography and attributes are reluctant to step back to an intermediate form for managing their data. Consequently, attention is given in this report to the development of a method of incorporating transportation system changes directly to existing application- specific networks. Close

• 3. [Article] A Framework for GIS-T Data Sharing

  This paper develops a framework and principles for sharing of transportation data. The framework is intended to clarify roles among participants, data producers, data integrators, and data users. The principles ...

  Citation × Citation Citation Abstract Copy Title: A Framework for GIS-T Data Sharing Author: Dueker, Kenneth, Butler, J. Allison Year: 2000 This paper develops a framework and principles for sharing of transportation data. The framework is intended to clarify roles among participants, data producers, data integrators, and data users. The principles are intended to provide guidance for the participants. Both the framework and the principles are based on an enterprise GIS-T data model that defines relations among transportation data elements. The data model guards against ambiguities and provides a basis for the development of the framework and principles for sharing of transportation data. There are two central principles. First is the uncoupling of graphics, topology, position, and characteristics. Second is the establishment of a schema for transportation features and their identifiers. An underlying principle is the need for a common data model that holds transportation features—not their graphical representations—as the objects of interest. Attributes of transportation features are represented as linear and point events that are located along the feature using linear referencing. Sharing of transportation data involves exchange of relevant transportation features and events, not links and nodes of application-specific databases. Strategies for the sharing of transportation features follow from this approach. The key strategy is to identify features in the database to facilitate a transactional update system, one that does not require rebuilding the entire database anew. This feature-oriented enterprise GIS-T database becomes the basis for building separate application-specific network databases. Title: A Framework for GIS-T Data Sharing Author: Dueker, Kenneth, Butler, J. Allison Year: 2000 This paper develops a framework and principles for sharing of transportation data. The framework is intended to clarify roles among participants, data producers, data integrators, and data users. The principles are intended to provide guidance for the participants. Both the framework and the principles are based on an enterprise GIS-T data model that defines relations among transportation data elements. The data model guards against ambiguities and provides a basis for the development of the framework and principles for sharing of transportation data. There are two central principles. First is the uncoupling of graphics, topology, position, and characteristics. Second is the establishment of a schema for transportation features and their identifiers. An underlying principle is the need for a common data model that holds transportation features—not their graphical representations—as the objects of interest. Attributes of transportation features are represented as linear and point events that are located along the feature using linear referencing. Sharing of transportation data involves exchange of relevant transportation features and events, not links and nodes of application-specific databases. Strategies for the sharing of transportation features follow from this approach. The key strategy is to identify features in the database to facilitate a transactional update system, one that does not require rebuilding the entire database anew. This feature-oriented enterprise GIS-T database becomes the basis for building separate application-specific network databases. Close

• 4. [Article] Issues in Calculating Traffic Impact Fees: A Review of the Literature

  Over time, the concern has grown that government is not funding infrastructure investment in United States at a sufficient level. Funding of infrastructure has been a joint effort of all levels of government, ...

  Citation × Citation Citation Abstract Copy Title: Issues in Calculating Traffic Impact Fees: A Review of the Literature Author: Rufolo, Anthony M., Lawson, Catherine T. Year: 1992 Over time, the concern has grown that government is not funding infrastructure investment in United States at a sufficient level. Funding of infrastructure has been a joint effort of all levels of government, but reductions in the federal contribution (after adjusting for inflation) have shifted more of the cost onto state and local governments. Many studies have identified massive funding requirements that are not being met. The failure to meet requirements would be rational if they are based on standards of service which are set unrealistically high or on other conceptual errors; however, failure to provide the funding likely to result in a deterioration in the level of service which is provided. In response to the demand for infrastructure and the the reduced availability of other funding sources, many local governments have started levying charges on new development for the purpose of funding off-site infrastructure requirements. Title: Issues in Calculating Traffic Impact Fees: A Review of the Literature Author: Rufolo, Anthony M., Lawson, Catherine T. Year: 1992 Over time, the concern has grown that government is not funding infrastructure investment in United States at a sufficient level. Funding of infrastructure has been a joint effort of all levels of government, but reductions in the federal contribution (after adjusting for inflation) have shifted more of the cost onto state and local governments. Many studies have identified massive funding requirements that are not being met. The failure to meet requirements would be rational if they are based on standards of service which are set unrealistically high or on other conceptual errors; however, failure to provide the funding likely to result in a deterioration in the level of service which is provided. In response to the demand for infrastructure and the the reduced availability of other funding sources, many local governments have started levying charges on new development for the purpose of funding off-site infrastructure requirements. Close

• 5. [Article] Improving Travel Information Products via Robust Estimation Techniques

  Traffic-monitoring systems, such as those using loop detectors, are prone to coverage gaps, arising from sensor noise, processing errors and transmission problems. Such gaps adversely affect the accuracy ...

  Citation × Citation Citation Abstract Copy Title: Improving Travel Information Products via Robust Estimation Techniques Author: Maier, David, Tufte, Kristin A., Fernández Moctezuma, Rafael J. Year: 2009 Traffic-monitoring systems, such as those using loop detectors, are prone to coverage gaps, arising from sensor noise, processing errors and transmission problems. Such gaps adversely affect the accuracy of Advanced Traveler Information Systems. This project will explore models based on historical data that can provide estimates to fill such gaps. We build on an initial study by Mr. Rafael J. Fernandez-Moctezuma, using both a linear model and an artificial neural network (ANN) trained on historical data to estimate values for reporting gaps. These initial models were 80% and 89% accurate, respectively, in estimating the correct speed range, and misclassifications were always between adjacent speed ranges (in particular, the free-flow range and congested range were never confused). Going forward, we will investigate other non-linear models, such as Gaussian Mixtures, that provide further statistical metrics, in contrast to the uninterpreted weights of ANNs. This work will exploit the Portland Transportation Archive Listing (PORTAL) at the Intelligent Transportation Systems Laboratory at PSU. Dr. Tufte helps supervise development of PORTAL, and Mr. Fernandez used PORTAL data in his study. PORTAL holds more than two years of Portland-area freeway-loop-detector data at both detailed and aggregated levels, and is an ideal resource for the proposed work. Initially we will be building and testing estimators in off-line mode. We will select a highway segment (comprising multiple detector stations) that is representative in terms of pattern of outages. We will build models for this segment, then examine their performance on estimates for synthetic gaps (so we can compare estimates to reported values). Later, using live loop-detector data (which PORTAL supports), we will work towards on-line estimation over the local freeway network, which requires computing estimates in a timely manner. Our end target is improvements in end-user travel information products, such as the Portland-Metro Speed Map on ODOT's Trip Check. Our main evaluation metric will be the trade-off curve bewteen accuracy of prediciton and percentage of gaps that can be filled. This research supports national surface-transportation research priorities, including the Systems Management Information area (ITS JPO). Within that area, it relates to (2) Data Management (techniques and guidance for processing and managing data associated with highway and transit monitoring) and (5) Data Dissemination (exchanging information about transportation services and providing that information to travelers). [Page 3-15, U.S. Department of Transportation Research, Development, and Technology Plan, 6th Edition] Title: Improving Travel Information Products via Robust Estimation Techniques Author: Maier, David, Tufte, Kristin A., Fernández Moctezuma, Rafael J. Year: 2009 Traffic-monitoring systems, such as those using loop detectors, are prone to coverage gaps, arising from sensor noise, processing errors and transmission problems. Such gaps adversely affect the accuracy of Advanced Traveler Information Systems. This project will explore models based on historical data that can provide estimates to fill such gaps. We build on an initial study by Mr. Rafael J. Fernandez-Moctezuma, using both a linear model and an artificial neural network (ANN) trained on historical data to estimate values for reporting gaps. These initial models were 80% and 89% accurate, respectively, in estimating the correct speed range, and misclassifications were always between adjacent speed ranges (in particular, the free-flow range and congested range were never confused). Going forward, we will investigate other non-linear models, such as Gaussian Mixtures, that provide further statistical metrics, in contrast to the uninterpreted weights of ANNs. This work will exploit the Portland Transportation Archive Listing (PORTAL) at the Intelligent Transportation Systems Laboratory at PSU. Dr. Tufte helps supervise development of PORTAL, and Mr. Fernandez used PORTAL data in his study. PORTAL holds more than two years of Portland-area freeway-loop-detector data at both detailed and aggregated levels, and is an ideal resource for the proposed work. Initially we will be building and testing estimators in off-line mode. We will select a highway segment (comprising multiple detector stations) that is representative in terms of pattern of outages. We will build models for this segment, then examine their performance on estimates for synthetic gaps (so we can compare estimates to reported values). Later, using live loop-detector data (which PORTAL supports), we will work towards on-line estimation over the local freeway network, which requires computing estimates in a timely manner. Our end target is improvements in end-user travel information products, such as the Portland-Metro Speed Map on ODOT's Trip Check. Our main evaluation metric will be the trade-off curve bewteen accuracy of prediciton and percentage of gaps that can be filled. This research supports national surface-transportation research priorities, including the Systems Management Information area (ITS JPO). Within that area, it relates to (2) Data Management (techniques and guidance for processing and managing data associated with highway and transit monitoring) and (5) Data Dissemination (exchanging information about transportation services and providing that information to travelers). [Page 3-15, U.S. Department of Transportation Research, Development, and Technology Plan, 6th Edition] Close