Under joint safety regulations issued by the Ministry of Transport and Ministry of Public Security, what is the mandatory night operating restriction for long-distance intercity passenger coaches (长途客运车辆夜间通行规定)?

1. They must drive at maximum speed between 02:00 and 05:00 to avoid traffic
2. Passenger coaches may operate without restriction if headlights are working
3. Long-distance passenger coaches and sleeper buses are strictly prohibited from operating on expressways and highways between 02:00 and 05:00, or must implement an approved relay driver system (02:00至05:00停止运行或接驳运输)
4. They must only carry freight cargo between 02:00 and 05:00