The Federal Motor Carrier Safety Administration is on track to launch its study of the 34-hour restart, said Martin Walker, chief of the agency’s research division.

Walker said drivers and carriers are showing interest in participating in the naturalistic study that Congress ordered when it suspended the more restrictive restart that went into effect in 2013.

The 2013 rule said that if a driver takes a 34-hour restart he must take off two periods between 1 a.m. and 5 a.m., and that the restart could only be used once a week. FMCSA put that provision in place because it had research indicating that nighttime sleep provides better recuperation than daytime sleep.

At the urging of American Trucking Associations, Congress suspended the provision while the study is under way. ATA argued that the provision cuts productivity and does not improve safety.

Walker said the agency will let a contract for the study this month. The study will compare five months of experience by drivers operating under the more restrictive rule to those working under the current rule.

He said FMCSA is looking for drivers who routinely drive 60 to 70 hours a week, and at night, as well as carriers that will support those drivers.

The agency has set up a website that spells out the terms of the study and provides links for more information.

Walker also said the agency will address another restart issue in another study.

ATA contended that the 2013 restart hurt safety by putting drivers on the road during early morning rush hour, thus increasing their risk exposure. Congress did not specifically ask for research on this possible risk, but the agency plans to look at it in an additional study it is planning, Walker said.