The primary purpose of a speed limit is to remind drivers to control their speed reasonably and prevent the dangers associated with speeding on subsequent roads. It stands as a crucial and indispensable element of road transportation safety.

The speed limit is determined by the traffic department based on the actual conditions of a road section.

It establishes safe and reasonable speed requirements through road signs or electronic navigation to alert drivers that they are about to enter a specific road section. Typically, a speed limit refers to the maximum speed allowed, but highways may also have a minimum speed limit.

On highways where vehicles travel at high speeds, setting a minimum speed limit is essential to avoid slower vehicles becoming obstacles and causing tailgating issues.

Common road sections with speed limits include:

1. Entrance ramps of highways and primary roads.

2. Areas where traffic accidents frequently occur due to excessive speed.

3. Sharp curves, sections with restricted visibility, poor road conditions (such as damage, waterlogging, or slippery surfaces), long and steep slopes, and hazardous sections on the side of the road.

4. Road sections with significant interference from non-motorized vehicles, livestock, and other factors.

5. Areas more seriously affected by special weather conditions.

6. Road sections where technical indicators of highways are controlled by the road's design speed, which is lower than the limit specified in the design specifications. This includes areas with insufficient sight distance, as well as those passing through villages, towns, schools, bazaars, and other locations with high pedestrian activity.

Purposes of Setting Speed Limits:

1. Ensuring Safety:

The primary and foremost purpose of setting speed limits is to ensure safety. The speed limit establishes a target speed that drivers can achieve steadily and comfortably, promoting overall safety on the road.

2. Efficiency:

Efficiency is another goal of speed limits, encompassing both the speed at which a vehicle can reach its destination most rapidly and the maximum number of vehicles that can pass within a given time frame under the set speed limit.

While some may hold the belief that higher speeds lead to more vehicles passing, this is a misconception. In reality, maintaining a certain safety spacing between vehicles is crucial.

At slower speeds, the number of vehicles traveling within a unit of time is not significantly impacted.

However, at higher speeds, the safety spacing increases, resulting in fewer vehicles traveling within the same time frame. Therefore, the relationship between speed and the number of vehicles is more nuanced than a simple correlation.