For a number of years, Hong Kong has been using roadside sensors to detect vehicles with harmful emissions, and is pleased to report an improvement in its air quality.
Starting late in 2014, sensors that use infrared and ultraviolet beams to detect carbon monoxide, nitrogen oxide, and hydrocarbon levels in tailpipe exhausts of passing vehicles were installed on highway ramps. The system uses cameras to capture the license plate information in order to inform the vehicle owners of the need to repair their vehicles and pass an emissions test before the vehicles are pronounced roadworth. Since the enforcement program began, more than 16,000 high-emissions vehicles have been detected and 96% have been fixed and passed the compulsory emissions test.
Independent monitoring conducted in 2015 found that average concentrations of carbon monoxide and nitrogen oxides at roadside locations had dropped by 26 and 27 per cent respectively, compared to 2012 levels. Figures from a separate monitoring program, the Hong Kong Air Pollutant Emission Inventory, also show that carbon monoxide and nitrogen oxide emissions from road transport declined, by 50 and 34% respectively, between 2012 and 2015.
Yuhan Huang, from the University of Technology Sydney in Australia, has been analyzing the program and believes that the technology should be adopted in other countries as it is relatively low cost and offers a quick and straightforward way to clean up the air.
“I think it’s an especially good idea in big cities like Beijing, which have serious air pollution problems from transport,” Huang said.