Under Article 60 of the Road Traffic Safety Law Implementation Regulations, what is the mandatory placement distance for the reflective warning triangle behind a disabled vehicle on standard urban/rural roads versus expressways?

1. 50 to 100 meters behind on ordinary roads, and at least 150 meters behind on expressways (extending to 200+ meters at night or in rain/fog)
2. 5 meters behind on ordinary roads, and 20 meters behind on expressways
3. Directly on the vehicle's rear roof rack on all road types
4. Warning triangles are only required for hazardous chemical tankers, not passenger buses