Unsafe conditions exist on aggregate surfaced shoulders when material erodes either from vehicular means or from erosion caused by wind, rain, and other forces. Most of the material is unrecoverable and therefore wasted. This adds to the labor, equipment, and additional costs of maintaining the shoulder. The following results are from a study sponsored by the Mn/DOT Maintenance Operations Research Fund and the Mn/DOT Office of Materials
Based upon input from maintenance supervisors; the project monitored the field performance of several aggregates and stabilization treatments during a 2-year evaluation period. Materials were evaluated along straight sections, vertical, and horizontal curves where AADT conditions varied from 3,000 to 25,000.
Aggregate gradation, shoulder drop-off, and erosion were monitored. Measurements also included shoulder cross slope and photo documentation of shoulder condition.
