Section 32301 of the Moving Ahead for Progress in the 21st Century Act (P.L. 112-141) requires the Secretary of the U.S. Department of Transportation to complete a field study on the efficacy of the restart rule published along with additional changes to the Hours of Service rules on December 27, 2011, applicable to operators of commercial motor vehicles of property subject to maximum driving time requirements of the Secretary. Pursuant to Section 32301, the report describes the design, methods, research findings, and conclusions of the naturalistic field study.