Why did you slow down in the tunnel?
Generally speaking, you have to slow down when entering the tunnel and you can't change lanes. Because the tunnel is painted with a solid line, and the solid line is not allowed to change lanes. So we hardly overtake in the tunnel. But in many places in the south, tunnels are actually drawn with dotted lines. In other words, you can change lanes and overtake at will in the tunnel.
Follow the preceding cars in turn in the tunnel, and don't change lanes to overtake. Because there are few lanes in the tunnel and the view is relatively poor, you should slow down in advance before entering the tunnel, see the situation in the tunnel clearly, and keep a proper distance from the preceding vehicle at the specified speed.
According to road conditions and traffic needs, roads are divided into motor vehicle lanes, non-motor vehicle lanes and sidewalks, and motor vehicles, non-motor vehicles and pedestrians are divided into lanes. There are no motor vehicle lanes, non-motor vehicle lanes and sidewalks. Motor vehicles pass in the middle of the road, and non-motor vehicles and pedestrians pass on both sides of the road.