Through license plate recognition (LPR) system, this program collected vehicle information in specific districts, not only helping to notify owners that their high-polluting vehicles require vehicle inspection, but also making use of the vehicle survey to assess impacts and effects of exhaust control promoted in the air quality maintenance zones. Based on the vehicle survey results, this program drafted targets subject to regulation and control measures, and then invited the management department that planned zoning of locations to hold consultation meetings on feasibility of the control measures as well as assessment of their impacts and effects, and also conduct a survey on willingness. Focusing on the impacted interested parties, deliberation meetings were held to discuss the control of air quality maintenance zones. Through thorough communication and listening to different opinions, the impacts of control could be reduced so as to smoothly promote the control of mobile pollution sources in the air quality maintenance zones. After extending the assessment of impacts and effects based on the LPR survey results in 2020, this program completed the draft of announcement for Chimei Museum and Tainan Metropolitan Park on August 4, 2021, and subsequently on August 5, 2021 held a deliberation meeting with affected interested parties, discussing the zoning of areas and control measures to be promoted. On December 24, 2021, the Environmental Protection Administration approved the Environmental Protection Bureau of Tainan City Government to announce the designated air quality maintenance zones. Later on, the Bureau officially announced the zoning on January 3, 2022, and published that in the Municipal Gazette on January 6, 2022.
Through the installed LPR system as well as the established back-end information collection, notifications were sent to owners of unregulated diesel vehicles to receive vehicle inspection. The LPR system in combination with noise meter could inspect and regulate vehicle noise. Through compilation of LPR data as well as comparison and analysis of vehicle registration data, information of vehicles running in different districts and high air pollution maps can be provided to serve as a reference for future formulation of mobile pollution source control strategies and control measures for designation of air quality maintenance zones.
1. Program implementation schedule
This program was implemented from March 18, 2021 to December 31, 2021. As scheduled, all the tasks have achieved the target volume set out in the contract, and the main implementation results of different items are shown below.
2. Major implementation results
(1) In 2021 the total number of LPR-recognized vehicles were 1,350,081 (320,803 diesel vehicles, 1,018,665 motorcycles). After excluding those with invalid license plates and also screening out and comparing those with unique-number license plates, the total number of diesel vehicles was 55,470 and that of motorcycles was 367,764 (excluding the number of cars). Amongst the LPR-recognized samples of diesel vehicles in terms of vehicle type, light trucks account for 48.3%, big trucks account for 45.3%, and the percent of coaches and sedan cars was below 5.0%. With regard to phases of vehicles, phase-5 vehicles had the highest percent of 39.2%, followed by phase-3 vehicles at 17.8% and phase-6 vehicles at 14.3%. The percent of phase-1 vehicles was the lowest at 4.8%.
(2) Based on the LPR results in 2021, focusing on the areas and road sections having more phase-1 to phase-3 vehicles and having more vehicles without autonomous-management badges, potential road sections with medium- and high-polluting vehicles were mapped in order to strengthen inspection of the targeted high-polluting vehicles. After selecting from the potential road sections with more high-polluting phase-1 to phase-3 diesel vehicles, the high-polluting road sections in Yongkang District were Zhengbeiwu Road, Dawan Interchange, Yuxing East Road, Yongkang Incineration Plant, Heping East Road, Xinggong Road, Yongkang Interchange, Zhongzheng North Road, Wangtian Boulevard and Zhongzheng South Road, followed by Xinshi District and Annan District.
(3) In the diesel vehicle screening program using the map of potential medium- and high-polluting road sections, data analysis was made for the results of roadside spot checks on vehicles as well as visual judgment of smoke. Roadside spot checks on vehicles were performed for 17 times in total, whereas visual judgment of smoke were performed for 16 times. Among them, the effectiveness of roadside spot checks on vehicles was highest in Xinshi District, with rate of failing to pass inspection reaching 33.3%. As to visual judgment of smoke, the highest inspection effectiveness was in Yongkang District, with 100% of the inspected vehicles suspected of being the polluting ones; and it was followed 7.6% at Rende District. In the future LPR system shall continue to be installed in the potential medium- and high-polluting districts, so as to help notify the owners that their unregulated vehicles require inspection, and provide an inspection control route plan of diesel vehicles. These actions are hoped to enhance the acquisition rate of badges and accelerate the replacement of high-polluting vehicles.
(4) After screening, notifications were sent by surface mail to notify owners that their regulated vehicles require inspection; and notifications of penalties were sent by registered mail with advice of receipt to the owners who hadn’t had their motorcycles inspected regularly before due date as well as those hadn’t had their vehicles inspected even after receipt of the first notification. For the notifications sent for vehicle inspection, there were 9,000 diesel vehicle cases and 41,933 motorcycle cases in total. As to the vehicles receiving inspection after receipt of notifications in 2021, the inspection rate of diesel vehicles was 19.4% and the inspection rate of motorcycles was 66.2%. Besides, there were 81 diesel vehicles and 1,886 motorcycles urged for scrapping, achieving estimated emissions reduction effects of different pollutants, including 4.2 metric tons of PM10, 3.8 metric tons of PM2.5, 68.0 metric tons of NOX, 46.0 metric tons of CO, and 13.9 metric tons of NMHC.
(5) The data of the LPR results in 2021 show that the number of phase-1 to phase-3 diesel vehicles was apparently lower than those of 2020, and the number of phase-6 vehicles was tremendously increased, revealing that the rate of replacing old vehicles in 2019-2021 increased significantly.
(6) In 2019-2021 the number of diesel vehicles having acquired autonomous-management badges had increased yearly; and the unprecedented highest record was made in 2021, having 9,614 diesel vehicles acquired the badges. Apparently, sending notifications to the owners of the LPR-recognized and unregulated vehicles screened to have their vehicles inspected can enhance the management rate effectively.
(7) In 2021 the districts installed with motorcycle LPR system were Anping District, Zhongxi District, Rende District, Annan District, Yongkang District, East District, South District, Xinhua District, Xinshi District and Guiren District. The administrative districts having the highest number of LPR-recognized motorcycles not being inspected regularly was Annan District at a rate of 85.7%; and an average of 15%-25% was in other administrative districts. Focusing on the data of LPR-recognized samples, cross analysis was made for the motorcycles not being inspected regularly and the two-stroke motorcycles. As to the rate of LPR-recognized motorcycle samples not being inspected regularly and the rate of two-stroke motorcycles, the highest rates of them were both in East District and South District. As to two-stroke motorcycles not being inspected regularly(over 10 LPR-recognized motorcycles), the highest rate of them was in East District, South District, Guiren District and Yongkang District. Regarding the rate of motorcycles of different phases not being inspected regularly, the highest rate was the phase-3 to phase-5 motorcycles in East District not being inspected regularly within one year, and the second highest rate was the phase-4 to phase-5 motorcycles in South District and Yongkang District not being inspected regularly within one year.
(8) As shown from the LPR results in the air quality maintenance zones (Chimei Museum and Tainan Metropolitan Park) in 2021, the motorcycles aged below 10 years account for around 76.7%; the motorcycles aged above 20 years account for 2.8% only; the motorcycles not being inspected regularly account for around 52.2%; and the electric scooters account for around 3.5%. After cross analysis of the rate of LPR-recognized samples not being inspected regularly and those of different strokes, the rate of the LPR-recognized two-stroke motorcycle samples not being inspected regularly before due date was 65.4%, and the rate of four-stroke motorcycles not being inspected regularly before due date was 31.2%.
(9) Focusing on administrative districts screened for a larger number of LPR-recognized phase-1 to phase-4 old motorcycles, the potential road sections highly polluted by motorcycle exhaust were mapped. Among them, South District and Yongkang District were most highly polluted, followed by Guiren District. In South District, the highly polluted places were on Section 2 of Jiankang Road, Jinhua Road, Section 2 of Datong Road, Zhonghua South Road and Dacheng Road. In Yongkang District, the highly polluted places were Daqiao Railway Station, Southern Taiwan University of Science and Technology, Kunda Road, Zhonghua Road, Zhongshan Road, Zhongzheng Road, Minzu Road and Zhongshan 7th Street. In Guiren District, the highly polluted places were Section 3 of Zhongshan Road and Minquan North Road.
(10) There were 202 vehicles and machines on construction sites having completed basic information survey. Of them, 164 vehicles and machines were detected with black smoke by this program (the detection results showed that 55 vehicles and machines did not meet the excellent-grade standard, and the non-conformance rate was 33.5%), and 38 vehicles and machines were assisted by construction project to pump out fuel (all of which passed inspection).
(11) There were 1,354 pieces having completed replacement of diesel vehicles and pollution improvement (932 pieces being scrapped, including those with transfer of owner and replacement, 418 pieces being adjusted and repaired, and 4 pieces additionally installed with smoke filter).
3. Suggestions
(1) Improvement actions during the period of poor air quality
During the period of poor air quality (from October to March of the next year) it is suggested that according to the LPR results, potential polluting road sections can be zoned out on the upwind road sections around the various Air Quality Monitoring Stations (Tainan, Annan, Xinying, Madou) in order to provide a reference for conducting roadside spot checks on diesel vehicles and motorcycles every month, taking emergency response and improvement actions in the period of poor air quality, and drafting inspection and control measures for high-polluting vehicles.
(2) Expanding vehicle survey
It is suggested that the LPR results collected under the various Interchanges (Rende, Yongkang, Anding, Madou, Xinshi, Xinying as well as 86 and 61 Expressways) in the jurisdiction area can be compared with the data of different industrial districts so as to compare and check whether the diesel vehicles coming from the Interchanges and Expressways have entered the industrial districts in the jurisdiction area, and investigate the major groups and industry types of the vehicles mainly entering and leaving these districts. Subsequently, there should be unregulated diesel vehicles and high-polluting diesel vehicles being screened continuously for sending notifications to their owners to have their vehicles inspected, and provide a reference for the diesel vehicle planning stations to make inspection route plan.
(3) Vehicle survey and control plan in air quality maintenance zones
In response to the Environmental Protection Administration’s assessment on designating air quality maintenance zones in the harbor area for control of vessels and vehicles, as well as the school and hospital districts with frequent activities of sensitive group being prioritized as designated zones, it is suggested that focusing on the districts planned to be zoned and installed with LPR system, surveys can be made for the percentages of the diesel coaches (trucks), light trucks and fuel motorcycles of 5 years from the date of manufacture entering the planned control districts, as well as the percentages of industry type, vehicle type and vehicle registration of diesel vehicles in January and February 2022, in order to provide a reference for assessment of impacts after promotion of control as well as prioritizing districts for zoning. The details can help invite impacted interested parties to attend the subsequently held deliberation meetings. Through deliberation of improving control measures, the impacts caused by the control can be minimized.
