States may enact laws governing which of the following, provided they are no more burdensome than federal laws?

The correct answer is cargo liability. States are empowered to create their own regulations regarding cargo liability as long as these regulations do not impose more stringent standards than those established at the federal level. This is largely due to the principle that states have the authority to manage business operations within their borders, including contracts and liability issues, as long as they align with federal laws. Regulations surrounding cargo liability can include aspects such as the responsibilities of carriers in the event of cargo loss or damage.

Regarding the other areas mentioned, driver licensing and insurance requirements are more closely regulated at the federal level, with states being required to comply with the standards set forth by federal agencies such as the Federal Motor Carrier Safety Administration (FMCSA). Safety equipment standards are also largely dictated by federal regulations to ensure uniformity and safety on a national scale. In these areas, states may have some latitude to implement their own laws but cannot do so if they create a conflicting or more burdensome standard than federal law allows.