The old law professor eyed his class and stated, “The law is not about what is right or wrong, fair or just. The law is about what passes the legislature.”

Where one might read this as a distorted view of the law, it is actually what we all learned in high school civics. The constitution gives law-making powers to the legislature. The legislature, in turn, decides the scope of authority for each government agency, as well as the specific laws those agencies are to enforce.

The same civics lesson is played out at both the state level and the federal level. The state highway patrol, for example, gets its marching orders from the state legislature, which, in turn, derives its powers from the state constitution. The U.S. Constitution puts Congress in charge of law-making. Congress lays out the charter for each federal agency and also weighs in on specific issues, often expanding or refining the scope of an agency’s jurisdiction on that issue.

Take the Federal Motor Carrier Safety Administration. FMCSA was once the Office of Motor Carrier Safety within the Federal Highway Administration (FHWA). When Congress in January 2000 approved FMCSA as a separate agency within the U.S. Department of Transportation, it also adopted a statutory charter for FMCSA – what the new agency could and could not do, must and must not do.

So, what can FMCSA do? A look at the FMCSA webpage says its primary mission is to reduce crashes, injuries and fatalities involving large trucks and buses. That mission came from its statutory charter, found within the Motor Carrier Safety Improvement Act of 1999. There, Congress clearly listed what it felt were the shortcomings in motor carrier safety to that point, which it directed FMCSA to address.

But Congress also inserted into law some restrictions on how FMCSA could act. For example, “…the Federal Motor Carrier Safety Administrator shall not take any action that would impinge on the due process rights of motor carriers and drivers.” Courts have also weighed in. In the first Public Citizen vs. FMCSA case on hours-of-service (HOS), the court said FMCSA must consider the impact of regulations on driver’s health, a factor imposed by Congress on its FHWA predecessor though not expressly mandated in FMCSA’s own statute.

FMCSA similarly inherited oversight of brokers, freight forwarders and household goods movers, all mentioned in its charter. But nowhere in the Motor Carrier Safety Improvement Act of 1999 does the word “shipper” appear. So, how can FMCSA prohibit shippers and others from coercing drivers to violate HOS rules and other safety regulations?

The answer is our civics lesson. In any FMCSA final rule there is a section titled “Legal Basis for This Rulemaking.” In its rulemaking prohibiting coercion of commercial motor vehicle drivers, FMCSA cites MAP-21 (Moving Ahead for Progress in the 21st Century Act) of 2012, where Congress directed this result, expanding FMCSA’s reach to shippers on the specific issue of coercion.

Ultimate power — what a federal agency can and cannot do, must and must not do – resides with Congress. FMCSA can reach beyond trucks and buses when Congress, in the FMCSA charter or in a specific law, says it can. So, as FMCSA considers shipper responsibility for cargo securement within sealed containers and trailers, or when FMCSA weighs the complexities of driver detention at shipper/consignee facilities, the agency will first look at the powers given or denied FMCSA by Congress.