Motor vehicles must not exceed the speed limits indicated by speed limit signs or markings on the road.
When driving on highways, the highway should indicate the speed limits for each lane. The maximum speed limit is 120 km/h, and the minimum speed limit is 60 km/h. On highways, the maximum speed limit for small passenger cars is 120 km/h, for other motor vehicles it is 100 km/h, and for motorcycles it is 80 km/h. On roads with two lanes in the same direction, the minimum speed limit in the left lane is 100 km/h; on roads with three or more lanes in the same direction, the minimum speed limit in the leftmost lane is 110 km/h, and the minimum speed limit in the middle lane is 90 km/h. If the speed limit indicated by a road speed limit sign differs from the above lane speed limits, the speed limit indicated by the road speed limit sign shall prevail.
On roads without speed limit signs or markings, motor vehicles shall not exceed the following maximum speeds: 30 km/h on urban roads and 40 km/h on highways without a center line; 50 km/h on urban roads and 70 km/h on highways with only one lane for motor vehicles in the same direction.
The maximum speed of motor vehicles shall not exceed 30 km/h in the following situations, except for tractors, electric vehicles, and wheeled special-purpose vehicles, which shall not exceed 15 km/h: when entering or exiting non-motorized vehicle lanes, crossing railway crossings, sharp bends, narrow roads, or narrow bridges; when making a U-turn, turning, or descending a steep slope; when visibility is less than 50 meters in fog, rain, snow, sandstorms, or hail; when driving on icy or muddy roads; and when towing a disabled motor vehicle.
Speed limit signs must be scientifically validated. Where the difference between the speed limit on a special speed-limited section and the speed limit on an adjacent section exceeds 20 km/h, speed limit signs should be installed in a gradual transition to guide vehicles to decelerate smoothly, avoiding abrupt "cliff-like" speed limits. For speed limits on the same road section where the difference exceeds 30 km/h between different vehicle types, the difference should be adjusted to within 20 km/h, and the signage should be improved. Depending on road conditions, four-lane highways should preferably use a single speed limit or speed limits based on vehicle type; six-lane highways should preferably use speed limits based on vehicle type and lane; and eight-lane highways should preferably use lane-specific speed limits or a combination of speed limits based on vehicle type and lane.
Section speed measurement, as a technical means of speed limit management, determines whether a vehicle is speeding by measuring the average speed of a vehicle passing through a certain section. This can effectively prevent drivers from evading penalties by suddenly braking at fixed speed measurement points.
