EVALUATION OF MINOR IMPROVEMENTS (PART 8), GROOVED PAVEMENT SUPPLEMENTAL REPORT

A "before and after" technique was used to evaluate 322 lane-miles of grooved portland cement concrete pavement on State freeways in Los Angeles. In addition, 750 lane-miles of ungrooved PCC pavement were used as a "control". Accidents (fatal and injury only) were evaluated for a two-year before and after period on both the grooved and ungrooved sections of freeway. Grooving produced an average 69% reduction in wet pavement accident rates on the 23 projects studied. Dry pavement accident rates did not change. Sideswipe and hit object accidents had the largest reductions during wet weather. Grooving did not appear to have an adverse effect on motorcycle safety during either wet or dry conditions. A different method was developed to predict wet pavement accident rates after grooving on future projects. The method depends on accounting for any trends in the wet and dry pavement accident rates that have occurred in the past. Even after grooving, the wet pavement rates can be expected to be about four times the dry accident rates.

• Supplemental Notes:
  • Study conducted in cooperation with DOT, Federal Highway Administration.
• Corporate Authors:

  California Department of Transportation

  1120 N Street
  Sacramento, CA  United States  95814
• Authors:
  • Smith, R N
  • Elliott, L E
• Publication Date: 1975-9

Media Info

• Pagination: 55 p.

Subject/Index Terms

• TRT Terms: Before and after studies; Concrete pavements; Crash rates; Forecasting; Motorcycles; Pavement grooving; Pavements; Portland cement concrete; Side crashes; Traffic crashes; Wet weather
• Uncontrolled Terms: Wet pavements
• Subject Areas: Highways; Pavements; Safety and Human Factors;

Filing Info

• Accession Number: 00158118
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: CADOTTR2152-11-75-01Final Rpt.
• Contract Numbers: IX-2-3
• Files: TRIS, USDOT, STATEDOT
• Created Date: Oct 13 1977 12:00AM