The AAMVA CDL Manual's introduction to Section 8 describes a specific purpose for inspecting a tank vehicle before loading, unloading, or driving it. What dual purpose does the manual give?

AAMVA CDL Manual §8 intro (p. 8-8-1)

Unlike a dry van, a tank vehicle's cargo itself can become a safety hazard if the vehicle isn't sound, so the manual frames tank inspection as serving two goals at once: protecting the cargo being carried and protecting the vehicle's roadworthiness.