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South Dakota Department of Transportation
Project Synopsis

Title: Update of the Non-State Trunk Inventory
Project Researcher: Somitra Saxena, GIS/Trans, Ltd.
Project Manager: Daris Ormesher
Research Period: 4/5/2000 - 3/31/2001
Cost: $60,000.00

Problem Statement: The Office of Data Inventory is responsible for maintaining an inventory of all the highways off the state highway system. Over the years some of this information has become obsolete due to a lack of resources to keep the information updated. A portion of the information is in the process of being updated by the State Planning and Development Districts with the Global Positioning System (GPS) road track data collection effort, but there are significant data items that need attention such as road mileage and Functional Classification. Public road mileage such as State Parks and Corps Land for example, may not be represented in the database. These and other items need to be reconciled because their accuracy is in question. The new GPS data collection effort has completed 36 counties and is expected to have the data for the remaining counties collected in the summer of 2000.

Some of the important uses for this information are to develop Federal funding justification, the state certified mileage report, local roads needs analyses and funding studies, map generation, required Federal reporting (Highway Performance Monitoring System), truck weight impact, and emergency response. These uses and the supporting data items need to be reviewed to determine if they are sufficiently important to justify the effort required to correct them in the Non-State Trunk Road Inventory file (NSTRI). The level of effort and process required to correct the data also needs to be identified and accurately assessed.

The current NSTRI system interfaces with the Highway Performance Monitoring System (HPMS), Railroad Crossing Inventory and the HR14 system (mainframe programs) which is used for state and federal mileage reporting requirements. Programs currently exist on the mainframe computer, which supports the above interfaces.

There is a need to bring the new GPS road track data and the mainframe NSTRI database together into one consolidated Non-State Trunk database. All data items need to be evaluated to determine if they need to be collected or remain in the database. Maintenance of the database is required to keep the data current. Any changes to the non-state trunk system such as realignments, abandonment, or new developments need to be reflected in the database.

SDDOT needs to determine which data items need to remain in the consolidated Non-State Trunk database and the most cost effective approach to correct the most critical Non-State Trunk data items. From this analysis, a more informed decision can be made regarding the value, support, and cost for updating the data for all the counties and cities.

Findings: GIS/Trans Ltd. provided consultant services to integrate the existing NSTRI database with updated information from a recently completed GPS inventory. The first step was to review the current environment of the NSTRI and the data items contained in it, as well as the data items contained in the GPS inventory. Recommendations were made regarding the suitability of retaining certain data items and all data items were ranked in order of importance. Since there was no common key field in the databases, they could not be joined using standard database techniques. It was determined that using a Geographic Information System (GIS) to join the databases based on the location of the attribute sections was the most appropriate method to use. The GPS Inventory collected the road centerlines (basemap) with accurate road lengths (measures), and certain road characteristics as attributes. The GPS attributes could be placed directly on the basemap since their measures matched those of the basemap. The NSTRI method of locating attribute sections however, had to be converted into the same measurement system as the GPS. A Linear Referencing System (LRS) was created for the NSTRI which allowed the researchers to place the NSTRI data on the same basemap as the GPS data. Finally, the two databases could be joined by matching the route identifiers, and the measures for each attribute record. Upon determining that the databases could in-fact be joined, procedures for maintaining and updating the combined database were recommended. Resources required to maintain the database were also recommended.

Research Objectives:
1  Determine the data elements that should be maintained in a consolidated NSTRI database.
2  Determine a common reference between the current NSTRI database and the GPS collected data for all of South Dakota‚Äôs counties.
3  Determine standards and procedures for collecting and maintaining data in a consolidated NSTRI database.
4  Determine resources necessary to collect and maintain data for a consolidated NSTRI database.

Research Tasks:
1  Review and summarize literature relevant to data collection and maintenance of Non-State Trunk data.
2  Meet with the Technical Panel to review project scope and work plan.
3  Conduct interviews of SDDOT, FHWA, local government representatives, and the State Planning an Development Districts to determine data items that need to be collected and maintained in a consolidated Non-State Trunk database.
4  Develop list of data items that should be stored in the consolidated NSTRI database and rank in order of importance. The ranking should include cost of data collection, quality, accuracy, need and effort to collect and maintain a consolidated NSTRI d
5  Develop and document the policies and procedures for collecting and maintaining data for the consolidated NSTRI database and submit a technical memorandum to the technical panel.
6  Meet with the technical panel to review the proposed list of data items that need to be collected and the proposed methods to test the recommended maintenance standards and procedures.
7  Identify a common key or method for all South Dakota counties to interface between or consolidate the GPS collected data and the current NSTRI database.
8  Define and develop the procedure to consolidate or interface the two databases using the common key or interface method so that the consolidated NSTRI data will be available for use on all required computing platforms (i.e. mainframe and PC networks)
9  Recommend a plan to verify that the new data collection standards and procedures can be used to update the consolidated database. SDDOT will contract with the Planning Districts to collect the necessary data for verification of the new data collectio
10  Evaluate work completed in previous tasks and recommend the type, quantity, and cost of resources necessary to maintain the consolidated NSTRI database.
11  Prepare a final report and executive summary of the literature review, research methodology, findings, conclusions, and recommendations.
12  Make an executive presentation to the SDDOT Research Review Board at the conclusion of the project.

Documents Available:

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