It goes without saying that large commercial motor vehicles (CMVs) can cause a lot more harm than the standard vehicles we drive every day, and naturally, there are additional regulations for these commercial trucks. But who makes these regulations and enforces them?

The Short Answer: The government.

The Long Answer: The Federal Motor Carrier Safety Administration (FMCSA) is a specific agency, created by the US Congress for the explicit purpose of monitoring and regulating any and all trucking companies, bus companies, and any other entities that use vehicles for commercial purposes.

Now that is obviously a mouthful, so let's break it down into more manageable bites.

Congress Makes Laws, Executive Agencies Enforce Those Laws

In the most basic explanation, the US Congress creates laws and sometimes also establishes agencies to execute those laws under the direction of the president.

Congressmen are not experts in every field that they pass laws for, so they are often unable to determine how the law should be carried out. Additionally, the laws that Congress passes are typically worded in terms of a general goal such as, "we need the trucking industry to operate more safely." This is why they create administrations, within the executive branch, which will then create the regulations that enable them to enforce Congress's broad mandates.

Here is a very simplified example:

1. Congress recognizes that commercial motor vehicles (CMVs) have the potential to cause a lot of harm if they are driven and/or maintained poorly.
2. Congress passes a law that CMVs and commercial drivers need stricter safety standards.
3. To make that law a reality, Congress establishes the Federal Motor Carrier Safety Administration (FMCSA).
4. FMCSA now has the authority to create the rules and regulations that commercial trucks and truckers are expected to follow.

In a nutshell, the FMCSA is a government agency that was created to enforce the law passed by Congress. And the FMCSA creates the regulations which clarify/help realize the goals of Congress with respect to commercial vehicle safety.

It's worth mentioning that many constitutional scholars argue that when Congress delegates so much broad rule-making authority to an executive agency that this is a violation of the Non-Delegation Doctrine. We're inclined to agree, but the reality is that the federal judiciary has said this is permissible. So, as a practical reality, regulations created by the FMCSA are treated as having the same veracity and legitimacy as laws passed by Congress.