Traffic Forecasting Accuracy Assessment Research (2020) / Chapter Skim
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Pages 46-57
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From page 46... ...
I-34 The project team recommends that agencies responsible for traffic forecasts systematically archive those forecasts and collect observed data on project outcomes both before and after the project opens. A strong archival process ensures that the necessary details about project forecasts are preserved in a readily accessible format once each project has been opened to traffic.
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Archiving Traffic Forecasts and Associated Data I-35 • Silver. At the second archiving level, additional details and nuances specific to the project are recorded, as are assumptions about the forecast.
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I-36 Traffic Forecasting Accuracy Assessment Research 3.1.2 Silver Archiving Level Silver-level archiving builds upon the Bronze standard by recording details and nuances that otherwise would not be captured. This level of archiving is not recommended for all projects; however, it should be used for projects that are larger than typical projects or that represent new or innovative solutions that do not have a long track record of accurate forecasts.
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Archiving Traffic Forecasts and Associated Data I-37 The Gold level includes all of the Silver-level information plus an electronic archive that allows analysts to completely reproduce the forecast after project opening. The study team found that, when the original model runs were available, reproducing the forecasts was easier to achieve than originally assumed.
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I-38 Traffic Forecasting Accuracy Assessment Research the combined databases. In defining this common format, the project team reviewed information provided by agencies in Ohio, Wisconsin, Michigan, Virginia, Florida (District 4 and District 5)
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Archiving Traffic Forecasts and Associated Data I-39 Field Data Source Recommended Ohio DOT Wisconsin DOT Michigan DOT Virginia DOT Florida DOT (D4) Florida DOT(D5)
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I-40 Traffic Forecasting Accuracy Assessment Research another agency might have used a more detailed classification that distinguished among operational improvements, adding lanes, repaving, intersection changes, and other types of improvements. The first two points limited the analysis that could be conducted for this research, and the second two points were important to the design of the database.
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From page 53... ...
Archiving Traffic Forecasts and Associated Data I-41 • Increasingly, scientific journals are requiring that the data supporting a research paper be archived and made available to future researchers. The preferred method for doing this is by uploading the data to a public data repository that can store the data over the long term and provide access to upload or download the data through a stable URL.
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I-42 Traffic Forecasting Accuracy Assessment Research The project team developed five types of forecast cards: • Points of Interest, such as roadway segments or transit lines; • Projects, such as specific roadway expansions; • Scenarios, including information used to make the forecast and/or about the forecasting system; • Forecasts, consisting of predictions about the project outcomes at the points of interest at specific points in time (i.e., what the project is expected to do) ; and • Observations, which are points of data (usually traffic counts)
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Archiving Traffic Forecasts and Associated Data I-43 Figure I-7. Forecast card data schema.
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I-44 Traffic Forecasting Accuracy Assessment Research logically include a traffic forecast report or other documentation conforming to the Silver-level archiving standard. For select projects, the additional files might also include the files necessary to reproduce the associated model runs, bringing the archived information up to the Gold standard.
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Archiving Traffic Forecasts and Associated Data I-45 With this option, the data should be stored on a local network drive where it can be edited directly. Even with the local storage option, the project team recommends that agencies use a version control system (such as Git)
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