DEVELOPMENT OF THE PCA ROAD METER: A RAPID METHOD FOR MEASURING SLOPE VARIANCE

RESULTS OF THE AASHO ROAD TEST WERE DETERMINED IN PART BY MEASUREMENTS OF VARIATIONS IN LONGITUDINAL SLOPE OF PAVEMENT SURFACES AS MADE BY THE AASHO PROFILOMETER. LATER, A DEVICE KNOWN AS THE CHLOE PROFILOMETER WAS DEVELOPED BY MEMBERS OF THE ROAD TEST STAFF TO AFFORD A LESS EXPENSIVE METHOD FOR MEASURING SLOPE VARIANCE. BOTH PROFILOMETERS OPERATE AT A SPEED WELL BELOW THAT OF TRAFFIC. HIGHWAY TESTS CAN BE MADE ONLY WITH EXTREME PRECAUTIONS THAT ARE COSTLY TO THE OPERATING AGENCY AND TRAVELING PUBLIC. FURTHERMORE, THE DEVICES REQUIRE MULTIPLE OPERATING PERSONNEL, ARE EXPENSIVE TO ACQUIRE OR CONSTRUCT, AND NEITHER IS ABLE TO SURVEY LARGE MILEAGES OF PAVEMENT IN A SHORT TIME. THE PCA ROAD METER WAS DEVELOPED TO AFFORD A RAPID METHOD FOR MEASURING SLOPE VARIANCE. THE METHOD USES A SIMPLE ELECTROMECHANICAL DEVICE, INSTALLED IN A CONVENTIONAL PASSENGER AUTOMOBILE, WHICH MEASURES THE NUMBER AND MAGNITUDE OF ROAD-CAR DEVIATIONS. THESE ARE STATISTICALLY SUMMED AND CORRELATED WITH SLOPE VARIANCE MEASURED BY THE CHLOE PROFILOMETER. THE TEST AUTOMOBILE CAN BE OPERATED AT SPEEDS CONSISTENT WITH TRAFFIC AND WITHOUT EXTRA PERSONNEL. THE PCA ROAD METER IS NOT DIFFICULT TO CONSTRUCT, IS INEXPENSIVE, AND HAS BEEN TESTED AND COMPARED DURING THE PERIOD FROM JUNE 1965 TO JULY 1966 IN THOUSANDS OF MILES OF HIGHWAY USE. AT PRESENT, IT IS BEING USED IN EXTENSIVE STUDIES OF PAVEMENT PERFORMANCE FOR THE PORTLAND CEMENT ASSOCIATION. IN THIS PAPER, THE BASIC MECHANICAL AND ELECTRICAL FEATURES ARE DESCRIBED, RESULTS OF CORRELATIVE TESTS WITH THE CHLOE PROFILOMETER ARE PRESENTED, AND PHYSICAL LIMITATIONS ARE DEFINED AND DISCUSSED. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1967/189/189-007.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Surface Properties--Vehicle Interaction and presented at the 46th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Brokaw, M P
• Publication Date: 1967

Media Info

• Media Type: Print
• Features: Appendices; Figures;
• Pagination: pp 137-149
• Monograph Title: Design,Performance and Surface Properties of Pavement
• Serial:
  • Highway Research Record
  • Issue Number: 189
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Automobiles; Electric meters; Machinery; Measuring instruments; Pavements; Performance tests; Portland cement concrete; Profilometers; Slopes; Variance; Voltmeters
• Old TRIS Terms: Electrometers; Mechanical equipment
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00205503
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 29 1994 12:00AM