A tanker is stopped at a red light on an icy road, with the driver holding the brakes firmly and the tank partially filled. Based on how liquid surge works, what could still happen?

49 CFR 383.119(a) (effects of cargo surge on vehicle control); AAMVA CDL Manual Section 8.2.2, p.8-8-2

This is one of the more surprising facts in tank vehicle driving: a liquid wave can push a fully stopped, fully braked truck simply because the road offers little resistance. Drivers who don't know this may be caught off guard in icy weather, assuming a stop means the truck will stay still. Recognizing this risk is critical for safely managing stops in winter conditions.