Stabilization Procedures to Mitigate Edge Rutting for Granular Shoulders - Phase II

Project status


Start date: 04/01/08
End date: 12/31/10


Principal investigators:

Co-principal investigators:

About the research

Efforts to eliminate edge ruts are important for several reasons. Granular shoulders with rutting and drop-off may contribute to drivers losing control and running off the road. Possible results are property damage, injuries, and/or fatalities.

A multifaceted investigation was undertaken to develop recommendations for methods to stabilize granular road shoulders with the goal of mitigating edge ruts. Included was reconnaissance of problematic shoulder locations, a laboratory study to develop a method to test for changes in granular material stability when stabilizing agents are used, and the construction of three sets of test sections under traffic at locations with problematic granular shoulders.



  • Iowa Department of Transportation
  • Iowa Highway Research Board
Shoulder drop off along the pavement edge