Katie Johnson

In a recent study, Minnesota DOT researchers used lab and field tests to evaluate blends of recycled asphalt pavement (RAP) and virgin aggregate for use as gravel road surface layers. Maintenance costs for a 50% RAP blend and a 100% virgin aggregate surface were compared as part of an economic analysis, and two field studies analyzed the performance of blends with 15% to 80% RAP content.

Read the research report: Optimal RAP Content for Minnesota Gravel Roads, March 2019.

Vermont Agency of Transportation recently tested a lower-cost pavement maintenance approach, repaving a 40-inch-wide area along the right wheel path in each direction of a deteriorated roadway rather than repaving the entire surface. The treatment was successful, reducing rutting and cracking and extending the pavement’s service life.

Read the research report: Assessment of the 40″ Wide Paving Skid Box for Preventative Maintenance, December 2018.

Researchers for Minnesota DOT and the Minnesota Local Road Research Board have developed a spreadsheet tool to help local agencies effectively track and manage gravel roads. Designed to be flexible and customizable, the tool can be used to keep all maintenance and construction data about a gravel road system, as well as track costs.

See the project page: Gravel Road Management Tool, March 2019.

Ohio DOT is exploring using hard shoulders as additional traffic lanes to ease rush-hour congestion. Researchers evaluated procedures and equipment that would keep the shoulder clear of debris, assessing cost per mile, operating speeds, safety protocols, and operation during inclement weather.

Read the research report: Evaluation of Maintenance Procedures for Hard Shoulder Running, Phase 1, March 2019.