What warning sign tells a bus driver they are going too fast for a banked curve?

AAMVA CDL Manual Section 4.3.4 "Speed on Curves," p. 4-3; 49 CFR 383.117(a)(6)

A bus leaning toward the outside of a banked curve is a physical, immediate signal that speed must come down right now, before the bus loses traction or tips. Recognizing this cue can prevent a rollover in the moment, not just in hindsight.