A disabled Pennsylvania school bus is stopped just beyond a curve where approaching traffic cannot see it for 300 feet. How does PennDOT treat this situation?

1. It can be an unsafe position requiring evacuation because normal traffic should see the bus for 300 feet or more
2. It is always safer to keep students on the bus because the engine is off
3. It requires students to walk down the lane to warn traffic
4. It is safe if the bus is not touching a railroad track