In what case do the rules not require the bus driver to give a warning signal?
While stopping at the edge of the roadway.
Before rounding a section of road marked with a "Dangerous Turn" sign.✓Bonne réponse
Before converting to an adjacent traffic lane.
When driving along a set route.
Explication
A warning signal is required before starting from the roadside, moving into another lane, turning, or stopping because those actions change the vehicle's course or state. Merely following a bend marked as dangerous is not such a maneuver, so the sign calls for caution rather than a direction signal.