What is the national standard regarding driver smoking (including electronic cigarettes) inside an online ride-hailing vehicle?

1. Drivers may smoke freely whenever windows are rolled down halfway
2. Drivers are strictly prohibited from smoking in the vehicle at all times, whether carrying passengers or waiting for dispatch (车内严禁吸烟)
3. Drivers may smoke electronic cigarettes if the passenger is asleep
4. Drivers may smoke if they offer a cigarette to the passenger first