A COMPREHENSIVE STUDY OF ROADMETER ROUGHNESS NUMBER WITH RIDING COMFORT FOR INDIANA PAVEMENTS. FINAL REPORT

This study is third in a series investigating the relationship between pavement rideability and roadmeter roughness number (RN). It was found that the public rates jointed and unjointed concrete surfaces similarly. It also rates asphalt overlays over concrete and full-depth asphalt similarly. For a given RN, motorists are more tolerant of concrete pavements than asphalt pavements. The differences in rideability between compact cars, mid-size cars, full-size cars, small trucks, and large tandem axle dump trucks were determined. It was found that there is no difference between a person's rating technique based on type of occupation. Ten regression models, one for each vehicle type and main pavement type, were developed, estimating PSI as a function of RN. From these models, it was found that the average motorist in this study was more lenient in rating pavements than in the last few years. Roughness testing of fabricated forms to determine the calibration of a roadmeter did not prove to be an adequate method. The frequent testing of an actual pavement site proved to be a better method. The odometer calibration should be checked at least every two weeks. Equations were developed that convert RN30 to RN50. The fuel tank level does not affect RN significantly. Hot tire air pressures should be monitored frequently. Radial and biased tires produce significantly different RNs, as do different grades of shock absorbers.

• Supplemental Notes:
  • A 15-page executive summary of this study is also available.
• Corporate Authors:

  Indiana Department of Highways

  Indianapolis, IN  United States 

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Harness, M D
  • Gulen, S
  • Anderson, V L
  • Kercher, K J
• Publication Date: 1985-8

Media Info

• Pagination: 298 p.

Subject/Index Terms

• TRT Terms: Asphalt pavements; Bituminous overlays; Calibration; Concrete pavements; Drivers; Full-depth asphalt pavements; Reaction time; Riding qualities; Road meters; Vehicle size
• Uncontrolled Terms: Driver reaction
• Subject Areas: Highways; Pavements; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00457005
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: FHWA/IN/DRT-85/1
• Contract Numbers: 1(21), Part II
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 27 2004 9:38PM