Before the amendment of the Air Pollution Control Act in 2018, the concept of the clean zone in other countries were widely applied in Taiwan for regional mobile pollution source control. The main purpose is to apply self-management and strengthen inspections for reducing high-polluting mobile source.

After the amendment, the local authorities may set up air quality maintenance zones depending on the local conditions and pollution characteristics. The measure is mandatory, and the local government can directly prohibit the entrance of highly polluting mobile sources and establish other appropriate relevant control measures.

Once the measure is enacted, local authorities need time to coordinate and design the plan. The main purpose of the plan is to assess the following areas, such as scenic areas, sea ports, schools, hospitals, to protect sensitive groups and reduce exposure risks; moreover, the main control emission mobile sources are highly polluting vehicles and ships. (Figure 1)

In order to fully explain and remind the public of the relevant regulations of the air quality maintenance zones, the air quality maintenance zone signs and notice boards as shown in the figure below are developed (Figure 2).

Otherwise, to make the best use of technology, like automatic license plate recognition systems (Figure 3), to effectively economize manpower and increase accuracy.