When the yellow light is on, vehicles that have crossed the stop line can continue to pass;
When the red light is on, no vehicle is allowed to pass.
Source: Regulations for the Implementation of the Road Traffic Safety Law of the People's Republic of China.
Relevant information: When the motor vehicles in front stop to wait in line or drive slowly, they should queue up in turn. They are not allowed to overtake or cut in line from both sides of the vehicle in front, and they are not allowed to stop and wait at crosswalks or mesh lines. Motor vehicles at intersections and road sections with reduced lanes, in case of waiting in line in front of motor vehicles or driving slowly, one motor vehicle in each lane shall alternately enter intersections and road sections with reduced lanes.
Related knowledge: remember the proverb-stop at the red light and go green, let people walk on the sidewalk.