To effectively control the air pollution of diesel vehicles in Chiayi City, the roadside stop-and-inspection and visual inspection of diesel vehicles have been enforced together with the implementation of related control measures, such as self-management, control of school bus and public service vehicles, and establishment of air quality maintenance zones. The related inspections and controls were enforced to discover the vehicles with high pollution and facilitate their improvement for pollution reduction. At the same time, a license plate recognition system was used to chase down the diesel vehicles with potential pollution that have not been incorporated into government management and request the presence of the subject vehicle for inspection with a notification issued. The control of the emission pollution from diesel vehicles driving around the municipal districts of Chiayi City is achievable. Also, the owners of the old and used heavy-duty diesel vehicles were encouraged to replace, tune ＆ repair, and retrofit their vehicles with air pollution prevention devices, and apply for subsidies with assistance provided by the city government. By enforcing the inspection, advocation, and subsidy measures, the control over diesel vehicles was reinforced, and the vehicle owners were supervised and urged to enhance the routine maintenance ＆ repair of their vehicles. Thus, all diesel vehicles in use can meet the emission standards that upgrade the ambient air quality and achieves the goal of a clean environment. In order to better upgrade the sampling ＆ testing quality, facilitate and the tasks of emission sampling ＆ testing for diesel vehicles in this city and mitigate the impact of the emission pollution of diesel vehicles on the air quality in this city, the renewal of the emission sampling & testing dynamometer was made to replace the sampling & testing equipment that has been using more than 10 years. Besides that, the advocation and inspection operation for the idling stop at the locations in the municipal districts where the idling of diesel vehicles is easy to appear. Furthermore, the task of noise sampling & testing was carried out locally as well; and also, the inspection at nighttime was enforced jointly with the police station to attenuate the noise generated from the motor vehicles and provide the citizens with a quiet space. The results of the project from January 1, 2022 to December 15, 2022 are as follows: (1)2,483 diesel vehicles were sampled & tested at the station; wherein, 61 vehicles failed the sampling & testing at a failure rate of 2.5%; and issued the self-management label to 2,556 vehicles. (2)1,036 vehicles were pulled over for screening and selection to enforce the roadside stop-and-inspection task; wherein, 156 vehicles were sampled and tested (73.7% of them are diesel vehicles in Phase I to III) with 70 vehicles failing the sampling & testing at a failure rate of 44.9%. (3)204 diesel vehicles were screened and picked by visual emission inspection with the notification issued. (4)686,575 vehicles were enforced the inspection by the license plate recognition system; wherein, 2156 vehicles were notified to be inspected at the station. (5)1,006 vehicles were enforced the idling stop inspection, 20 sessions of advocation for idling stop were made on campuses, and 509 vehicles in total received the advocation. (6)The dynamometer-related renewals were satisfactorily accepted on August 24 and officially put into use on August 26. Since the establishment of the Chiayi City Clean Air Promotion Committee, the Chiayi municipal government has committed to reducing the health hazards from air pollution to the citizens; and the emission from diesel vehicles among mobile pollution sources is also the most criticized by the public. Through various means of inspection and advocation, this project will force diesel vehicles entering and leaving the municipal districts to receive and pass the sampling & testing, and further obtain the self-management label. It is expected to ensure that the emission status of diesel vehicles entering and leaving Jiayi City can meet the emission standards and reduce the pollution sources in the municipal districts. This year, the mainly targeted vehicles were the old vehicles in Phase I, II, and III with high pollution. Meanwhile, an advocation to stress the subsidies for replacing old heavy-duty diesel vehicles offered by the Environmental Protection Agency, the subsidy policy for tuning & repairing the fuel control system, and the installation of air pollution prevention equipment have been jointly enforced to reduce pollution so as to effectively achieve the goal of pollution reduction. The pollution emission reductions enforced in this project are PM10 11.92 metric tons, PM2.5 10.59 metric tons, NOx 158.55 metric tons, NMHC 14.31 metric tons, and CO 55.53 metric tons.

Diesel vehicles, Air pollution, Autonomous management, air quality maintenance zone