The plan details the assessment technologies that will be used, study procedures, and the sampling plan and data analyses involved.
Congress ordered the agency to conduct the naturalistic study when it suspended the more restrictive restart that had gone into effect in 2013.
That rule required any driver taking a 34-hour restart to take off two periods between 1 a.m. and 5 a.m. and limited the restart to once a week. FMCSA put that provision in place on the basis of research indicating that nighttime sleep is more recuperative than daytime sleep.
Those restrictions were rolled back in December by Congress and will remain so until FMCSA completes the mandated study of the rule or until September 30 of this year, whichever comes later.