Incidents, maintenance, and environmental control
An immobilized vehicle becomes a signal problem
A broken-down vehicle is a hazard. Make it visible to other drivers as quickly as possible.
What to watch for
The question mentions a breakdown, emergency lights, warning triangles, or stopping on the shoulder.
The rule
The rule explains exactly how to answer any question of this type — and why the obvious wrong answer fails.
See the rule →Common trap
Don't focus on fixing the vehicle while other drivers still cannot see the hazard.