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South Dakota Department of Transportation
Project Synopsis
SD1998-14


Title: Verification and Calibration of the ARAN Road Profiler
Project Researcher: ,
Project Manager: Blair Lunde
Research Period: -
Status:
Cost: $0.00

Problem Statement: The Needs Book is used to verify existing conditions and much of the data is extracted from the roadway environment system (RES) database. Decisions regarding the Statewide Transportation Improvement Program (STIP) are based upon this data. In this year's Region inspections, it was noticed that in certain situations that the road profile data entered into the RES system was inaccurate. The problems identified were with the faulting and rutting data. This research study is needed to verify that the ARAN Road Profiler can correctly measure fault and rut and to review setup and calibration procedures to insure that accurate information is collected throughout the collection season.

For example, in the faulting data, one segment was plotted and it showed that in a tenth mile segment there should be approximately twenty-six faults identified. The automated faulting software identified a maximum of thirteen faults in a tenth mile for this project. For some road segments that were in question the profile plots showed slab curl or slab warp. Slab curl is defined as the slab curling upward from the center of the slab to the joints. Slab warp is defined as the downward curling of the slab from the center to the joints. The faulting software was not intended to identify slab curl or warp since they are different distresses exhibited by concrete pavements but a better estimate of the actual faulting was expected.

The rut information provided by the ARAN road profiler depicted less rut than visual inspection provided. Two situations were identified that indicated a need for research. In the first the current data showed no rutting but visually there appeared to be rutting and the data from the old profiler indicated a tenth of an inch rut throughout the project. The second was a situation where there was shoving in the outer wheel track. The road profiler will not be able to pick up the full amount of rut in this situation because the profiler uses just three data points and is not capable of picking up rutting caused by shoving.

In addition to these concerns, research study SD96-03, Review of SDDOT's Field Collected Roadway Data, recommended that protocols be adopted for the profile data. This study will provide the protocols to fulfill these recommendations.



Findings:

Research Objectives:
1  To determine how profile equipment identifies faulting, rutting and actual profile and to identify the limits of the equipment in making these measurements.
2  To verify that data collected by automated equipment is accurate and representative of actual conditions.
3  To review and to recommend changes to calibration and operating procedures for operators’ daily use.

Research Tasks:
1  Conduct a literature search to identify possible changes to calibration and verification procedures.
2  Meet with the Technical Panel to discuss the proposed work plan.
3  Review ARAN documentation and meet with department personnel and telephone Roadware representatives to determine methods used to identify faults and rut depths.
4  Determine and lay out test sections to be used for equipment verification
5  Perform rod and level and Dipstick surveys, and compare to ARAN data
6  Recommend methods of using automated equipment to identifying slab curl and warp.
7  Recommend calibration procedures for automated data collection equipment.
8  Prepare a final report and executive summary of the literature review, research methodology, findings, conclusions, and recommendations.

Documents Available:

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