According to Article 78 of the PRC Road Traffic Safety Law Implementation Regulations, what are the lane usage and maximum speed rules for heavy goods trucks on expressways?

1. Heavy trucks must operate in the right-hand designated lane(s) and must not exceed a maximum speed of 100 km/h
2. Heavy trucks may cruise indefinitely in the far-left overtaking lane at speeds up to 120 km/h
3. Heavy trucks have unrestricted lane choice and are exempt from posted expressway minimum speed limits
4. Heavy trucks must drive on the emergency shoulder whenever their speed falls below 90 km/h