TRB conducted a webinar on April 4, 2012, that explored methods to reduce sediment erosion from native and aggregate surfaced low-volume roads. Contact Reggie Gillum at RGillum@nas.edu to request a recording of the webinar. 

This webinar will explore research conducted in the Pacific Northwest and Pennsylvania that tested alternative unbound aggregate treatments for the road surface and compared sediment production from these alternatives to untreated road surfaces. The first webinar presentation covers research on roads in Oregon and Northern California where the surfacing treatments were designed to minimize subgrade sediment mixing and runoff. The second webinar presentation will explore research on roads in Pennsylvania where “driving surface aggregate,” a densely-graded unbound wearing course aggregate specification, was tested over time for sediment runoff. 

Webinar learning objective:

Given specific low volume road characteristics, the participant should be able to accurately identify methods to reduce erosion from a native or aggregate surfaced road.

Webinar panelists and presentation descriptions:

Elizabeth Myers Toman, The Ohio State University will present “Reducing Sediment Production from Forest Roads during Wet-Weather Hauling.”

This presentation describes research conducted in the Pacific Northwest to test alternative designs for unbound aggregate pavement for forest roads to minimize sediment production during wet weather use. Sediment production from side-by-side plots of alternative pavement treatments was measured and compared. Results indicate that pavement integrity plays a key role in sediment production and the “environmental failure” of unbound aggregate roads.

Steve Bloser, Pennsylvania State University, Center for Dirt and Gravel Road Studies will present “Road Sediment Reduction with the use of Driving Surface Aggregate.” 

This presentation focuses on research conducted in Northern Pennsylvania using a rainfall simulator on unbound aggregate roads.  Runoff was quantified on native surfaced roads and at intervals of one month, one year, and two years after the placement of a densely graded unbound aggregate (Driving Surface Aggregate).  After aggregate placement, results showed significant sediment reductions in road runoff for the duration of the study.

Moderated by Michael Long, Oregon Department of Transportation

Questions? Contact Reggie Gillum at RGillum@nas.edu.