Some breakdowns require calling 911 before calling roadside. Active traffic lanes (no shoulder available). Areas with active crime issues. Severe weather scenarios where the vehicle position is dangerous.
Police on scene can shut down a lane, provide a flashing-light buffer that makes the roadside response much safer, or escort you to a safer location.
After the police are on scene, then call roadside. The dispatcher coordinates with police timing — the tow truck arrives after the safe zone is established.
Don't try to handle dangerous-location breakdowns yourself. The risk of being struck by another vehicle in an active traffic lane is real and significant.
If you can't move the vehicle and can't safely exit, stay buckled inside, call 911 first, then call roadside with the police case number.