What does the yellow background with black text '30km' traffic sign indicate?

[Tim]

The yellow background with black text '30km' sign indicates an advisory speed limit, suggesting the recommended speed for drivers to pass through that particular road section as advised by traffic authorities. Below is a relevant introduction to road traffic signs: 1. Main signs: (1) Warning signs: Serve as warnings, alerting vehicles and pedestrians to potential hazards. They feature a yellow background with black borders and black symbols, shaped as an upward-pointing equilateral triangle. (2) Prohibition signs: Prohibit certain actions. Except for a few exceptions, these signs have a white background, red circle, red bar, and black symbols overlaid on the bar; shapes include circles, octagons, and downward-pointing equilateral triangles. (3) Directional signs: Provide directions, indicating the path for vehicles and pedestrians. They have a blue background with white symbols; shapes vary between circles, rectangles, and squares. (4) Guide signs: Offer route guidance, conveying information about direction, location, and distance. Typically, they feature a blue background with white symbols (except for milestones and hundred-meter posts); expressway signs usually have a green background with white symbols. Shapes are generally rectangles and squares, except for location identifiers, milestones, and merge/divergence signs. These signs are placed near road sections or intersections where directional, location, or distance information is needed. (5) Tourist area signs: Provide directions and distances to tourist attractions. They have a brown background with white characters and symbols; shapes are rectangles and squares. (6) Road construction safety signs: Notify about road construction zones, reminding drivers and pedestrians to exercise caution. 2. Auxiliary signs: Used when main signs cannot fully convey or indicate their content, these signs ensure traffic safety and smooth flow. They have a white background with black text and borders, shaped as rectangles, and are placed below main signs to provide supplementary information.

[FaithAnn]

I see a lot of these yellow signs with black 30km markings on the road, especially in construction zones. They indicate a temporary speed limit of 30 kilometers per hour. The biggest difference from regular speed limit signs is the background color—construction zones use eye-catching yellow panels with black numbers. Traffic regulations define this color combination as exclusive to road work areas, making it more warning than the common white background with red circle signs. Take these signs seriously, as there are usually construction vehicles or barriers ahead, and speeding through is particularly dangerous. Additionally, temporary speed limit zones end with a specific speed limit termination sign, and you must maintain a speed below 30 km/h until you see this sign.

[ChloeLynn]

The yellow sign with black text indicating 30km/h is a temporary construction speed limit sign. I dread encountering this sign the most during long-distance drives, as it signals road maintenance ahead. According to national standards, such signs must use fluorescent yellow background with black text, specifically for areas with ongoing worker operations. The key difference is that while regular speed limit signs are for daily traffic control, these yellow signs indicate immediate hazards ahead. Last week on the highway, I saw three of these signs placed consecutively every 500 meters, followed by a road roller blocking the lane. Now I've developed a habit: whenever I spot a yellow speed limit sign, I ease off the accelerator and turn on the hazard lights to alert following vehicles.

[Gia]

This belongs to the special signage for road construction. Recently, while taking my child to school, I happened to encounter municipal workers repairing the road. Several yellow signs with black lettering indicating a 30km speed limit were erected. The construction crew explained that the yellow background signifies temporary traffic control, distinguishing it from permanent speed limit signs with white backgrounds. The number 30 indicates the maximum speed limit, with the unit 'km' marked below for better visibility. It's important to note that this speed limit applies from the point where the sign is placed and typically extends to a safe distance beyond the construction zone. I personally witnessed a car speeding through, and the flying gravel nearly hit a worker.