In accordance with Article 45 (1) of the Air Pollution Control Act, competent authorities at all levels may perform non-periodic air pollutant emission testing or inspections of in-use mobile pollution sources at car parks or stations, at airports, on roadways, in port zones, on water bodies, or at other appropriate locations, or may require the owner of vehicles that is suspected of polluting to undergo testing at a designated location by a designated deadline. The regulations mentioned above have authorized the competent authorities at all levels to carry out a non-periodic inspection or tests at appropriate locations, and randomly conduct blockage inspection of the mobile pollution sources, such as diesel vehicles and motorcycles. If the vehicle fails the on-site inspection, the result shall be reported on the spot and improvement within a time limit may be required.
It includes visual inspection, self-management inspection, roadside inspection for Non-periodic inspection of in-use diesel vehicles . Statistics of diesel vehicle inspection data given by the Environmental Protection Bureaus in various counties and cities in the past 6 years show that the national failure rate had decreased from 6.1% in 2014 to 4.6% in 2020.