HIGHWAY SHOULDERS AS VIEWED BY THE SOIL ENGINEER

SHOULDER DESIGN TO SATISFY REQUIREMENTS OF STRENGTH AND SAFETY GIVE MICHIGAN SHOULDER STRUCTURE A DUAL PURPOSE. CLIMATIC CONDITIONS IN MICHIGAN DICTATE A MINIMUM SUBBASE THICKNESS OF TWELVE INCHES OVER CLAY SUBGRADE SOILS. GOOD SUBGRADE DRAINAGE REQUIRES THAT THE SUBBASE BE BUILT OF FREE-DRAINING GRANULAR MATERIAL AND THAT IT BE EXTENDED THROUGH THE SHOULDER. THE SUBBASE THUS BECOMES A PART OF THE SHOULDER STRUCTURE WHERE IT SERVES THE DUAL PURPOSE OF PROVIDING A DRAINAGE MEDIUM FOR THE TRAFFIC LANE AND LOAD BEARING STRENGTH FOR THE SHOULDER. THE USE OF TURF SHOULDERS IS USUALLY LIMITED TO LOWER TRAFFIC ROADS BECAUSE THEY ARE POOR LOAD BEARING SOILS DURING PERIODS OF WET WEATHER. THE MODERN TREND FOR SHOULDER DESIGN IS TOWARD AN EMPHASIS ON SHOULDER STRENGTH AND A WEAR RESISTING SHOULDER SURFACE. IT IS RECOMMENDED THAT SHOULDERS BE BUILT SUFFICIENTLY STRONG TO PERMIT A LOW COST SURFACING (SUCH AS A BITUMINOUS SEAL) TO CARRY THE LOCAL NORMAL TRAFFIC THROUGHOUT THE YEAR WITHOUT SPECIAL SEASONAL RESTRICTIONS.

Media Info

  • Monograph Title: Symposium on Highway Shoulders
  • Serial:
    • Issue Number: 151

Subject/Index Terms

Filing Info

  • Accession Number: 00203413
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 7 1994 12:00AM