SYSTEM FOR INVENTORYING ROAD SURFACE TOPOGRAPHY (SIRST)

An experimental trailer-mounted instrumentation system which surveys and records data on the roadway topography while being towed at normal highway speeds has been developed and tested. The system uses non-contacting electro-optical sensors to measure the relative height of the roadway surface along 12 selected paths which are spaced at intervals across the 12-ft. width of a normal traffic lane. Data on the cross slope and longitudinal slope of the surface and the direction of travel are obtained from a gyro-type inertial reference unit mounted on the instrumentation trailer. Compensation for vehicular bounce is obtained through use of a double integrated vertical accelerometer. At intervals of one (or two) feet along the roadway a solid-state data acquisition system samples the output from each height sensor; the roll, pitch and azimuth signals from the inertial reference system; the output from the accelerometer and the double integrated accelerometer signal. This data is digitized and recorded on a digital cassette type magnetic tape recorder. The cassette tape is used to provide an input to a computer for analysis and plotting purposes. Programs to permit computer plotting of the data to show the topography of the roadway surfaces were developed. Preliminary tests of the system have indicated height sensing accuracy to better than 0.01-in. (0.25mm) and the slope measurement accuracy to better than 0.2 deg. The tests have also demonstrated the capability of the system to collect data at 1-ft. intervals while being towed at speeds up to 35 mph and at 2-ft. intervals at speeds up to 55 mph. Further evaluation is needed to establish the accuracy under dynamic conditions and the correlation of the data on roadway surface topography with that determined by other measurement techniques. (FHWA)

• Corporate Authors:

  Southwest Research Institute

  6220 Culebra Road, P.O. Drawer 28510
  San Antonio, TX  United States  78228-0510

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • King, J D
  • CERWIN, S A
• Publication Date: 1982-8

Media Info

• Pagination: 269 p.

Subject/Index Terms

• TRT Terms: Accelerometers; Data collection; Digital computers; Electrooptic materials; Instrumentation; Instrumented vehicles; Inventory; Measuring instruments; Sensors; Slopes; Surface course (Pavements); Topography; Traffic lanes; Trailers
• Uncontrolled Terms: Electrooptical devices
• Old TRIS Terms: Digital systems
• Subject Areas: Freight Transportation; Highways; Pavements; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00367463
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-82- 62 Final Rpt., FCP 31H3-142
• Files: TRIS, USDOT
• Created Date: Nov 30 1982 12:00AM