A tank vehicle is equipped with baffles inside the cargo tank. What type of liquid surge are baffles designed to help control?

49 CFR 383.119(c) (differences in handling of baffled/compartmented tank interiors versus non-baffled vehicles); AAMVA CDL Manual Section 8.2.4, p.8-8-2

Knowing exactly what baffles do, and don't do, prevents a false sense of security behind the wheel. Baffles manage forward-and-backward surge, the type most directly tied to braking and accelerating. Misunderstanding this limits a driver's ability to anticipate the hazards baffles don't solve.