Drivers of ready-mix concrete trucks have been granted a limited exemption from the minimum 30-minute rest break provision of the hours-of-service regulations by the Federal Motor Carrier Safety Administration.

The exemption went into effect last week, on April 2, and will be in place through April 3, 2017 for mixer truck drivers who possess a sufficient safety rating with both FMSCA and its CSA safety-compliance program.

Under the terms and conditions of the exemption, drivers operating ready-mixed concrete trucks may use 30 minutes or more of on-duty ‘‘waiting time’’ to satisfy the requirement for the 30 minute rest break, provided they do not perform any other work during the break, FMCSA stated in its Federal Register notice.

The agency noted that this exemption affords “these drivers the same regulatory flexibility that 49 CFR 395.1(q) provides for drivers transporting explosives.”

The National Ready Mixed Concrete Association led the effort to obtain the exemption. “As a result of NRMCA’s efforts, much needed regulatory relief has been realized for the ready mixed concrete industry,” said NRMCA chairman Allen Hamblen.

Although the association welcomed the news, it cautioned that “the exemption as written is still only temporary” and making it permanent will “involve convincing members of Congress.”

NRMCA also pointed out that details of the exemption include language stating that if a driver passes the 12-hour threshold contained in the 100 air-mile logging exemption, he or she does not have to take the break, but rather can apply a previous 30-minute “waiting time” period toward the 30-minute break.

In addition, drivers utilizing the exemption must keep a copy of the exemption document in their truck.