The pollution of fine suspended particulate matter PM2.5 is one of the main concerns in the current poor air situation. According to the emissions of various pollution sources in Chiayi City estimated by TEDS10.1, mobile pollution sources PM2.5 emissions account for about 39.8% of the total emissions, of which the emissions of diesel vehicles account for 16.6%. Chiayi City is the smallest county in Taiwan with an area of only 60.03 kilometers, but the density of diesel vehicles ranks second in the nation. In order to reduce the risk of people being exposed to vehicle exhaust gas, this project has installed 14 sets of license plate recognition system in Chiayi City’s important external connection roads, Transit Center of Chiayi City, Lantan Scenic Area, Fruit and Vegetable Wholesale Market, and Chiayi Fish Market. Via the license plate recognition system, we can effectively understand the pollution situation of diesel vehicles driving in the Chiayi City, and notify the owners of vehicles without inspection records to report to inspection stations so as to gradually develop the habit of regular annual smoke exhaust inspection. Transit Center of Chiayi City is planned to be Chiayi City’s first air quality maintenance zone to further control diesel buses to reduce the risk of people being exposed to dense areas of diesel buses. The implementation results of the project from April 22, 2020 to December 15, 2020 are as follows: 1. 14 sets of license plate recognition system have been completed and are in normal operation. 2. The construction of the license plate recognition system receiving and processing center is completed and is in normal operation. 3. Implemented road license plate recognition and successfully identified 484,776 diesel vehicles. 4. After comparing the vehicle license plate recognition inspection and the environmental protection agency's inspection data, proactive inspection notices were sent to the owners of 2,109 vehicles without an inspection record for more than 10 years. 5. Completed the assessment of the mobile pollution source control measures implemented in the air quality maintenance zone, and a consultation meeting was held on September 10. 6. A technical transfer-training seminar was completed on November 27. 7. Two related publicity press release was issued.

License plate recognition system, Air Quality Maintenance Zone