Oil and gas drilling is booming these days, and the Federal Motor Carrier Safety Administration is proposing to revisit its hours-of-service guidance for carriers that serve the business.

The agency has for years granted two HOS exceptions to oilfield haulers.

One exception grants oilfield haulers a 24-hour restart after 70 hours of work in eight days. This applies to drivers who exclusively haul oil and gas equipment, such as pipe, as well as drivers who serve field operations.

The second exception says that specially trained drivers of vehicles spec'd to serve oil wells do not have to include waiting time in their on-duty time.

In response to queries from oilfield haulers whose business has expanded significantly as oil companies employ hydraulic fracturing, the agency is proposing to clarify these exceptions.

The 24-hour restart would apply to carriers that provide direct support to oil and gas well sites, including hauling the water that is used in the fracking process, and hauling waste away from the site.

The waiting time exception would apply only to drivers of equipment that is specially built for well service, and who have been trained in the operation of that equipment.

Drivers who haul supplies, equipment and materials such as sand and water would not be eligible for the waiting time exception, even if their trucks have been somewhat modified or if they have extra training.

The "proposal" is scheduled for publication in tomorrow's Federal Register. Comments will be due in August.