摘要: |
MnDOT Office of Transportation System Management (OTSM) desires to reduce the cycle time for collecting road data updates from county sources and, opportunistically, capture additional data about road and ancillary uses, e.g. bicycle access. Specifically, this project researched free or low-cost aerial or spatial data from government and other sources to determine if the imagery and spatial data would provide a source of sufficient resolution, accuracy and low cost to maintain MnDOT’s various mapping needs. Additionally, a process of comparing imagery (satellite or aerial imagery) to identify change detection (as shown in Figure 1 to illustrate how change detection may provide information on road realignment) was requested as a method of approaching the issue of maintaining geo-spatial road features and associated attributes. Currently, response for a request for updated road information from Minnesota counties can take six to nine months, and the information may contain errors or deficiencies. The lag in receiving information is compounded by the need to freeze data for reporting processes annually. In the best case, these data issues produce a 1.5 to 2-year lag between official MnDOT data products and local authoritative data. In the worst case, local responses are incomplete and inaccuracies persist over long periods. MnDOT requests a minimal amount of information from local governments to lessen the extensive labor impact of such requests, and requires a data maintenance source and process that allows accurate, repeatable, automated and timely updates of road data. The agency highly values the ability to automatically extract data from external data sources. |