Given the nation’s high density of motorcycles, the EPA has adopted a range of measures to restrict pollution emissions: gradually tightening emission standards for new vehicles, requiring all motorcycles to undergo regular exhaust emission inspections, encouraging citizens to report heavy-polluting motorcycles, raising the quality of fuels for vehicles, stepping up the phase-out of old two-stroke motorcycles, and promoting the use of low-polluting vehicles. Thanks to regular reinforced inspection at the local level, a total of 770,000 two-stroke motorcycles have been phased out in the past seven years, effectively reducing air pollution. As of the end of 2015, Taiwan had approximately 13.7 million motorcycles registered, 1.8 million of which were two-stroke. Motorcycles are mostly concentrated in Taiwan’s six major cities, with the most scooters being in New Taipei City, and the most two-stroke ones being in Kaohsiung City. In 2015, a total of 8,532 inspection operations were carried out resulting in the inspection of 4.77 million vehicles. These locally administered motorcycle inspections included patrols, roadside inspections, pulling over of suspect vehicles, and inspections based on vehicle registration plates. The rate of motorcycles showing up for regular inspection reached 69.5%. This consisted of 73.69% of the total four-stroke motorcycles compared to 54.48% of the total two-stroke ones. A total of 265,000 two-stroke motorcycles were retired as a result of regular inspections. Two-stroke motorcycles are heavy polluters, emitting 18 times the hydrocarbons and two times the carbon monoxide of four-stroke ones. To reduce the pollution emissions of two-stroke motorcycles, the EPA has been enforcing the fourth stage emission standards since 2004. Two-stroke motorcycles in Taiwan have already been taken off the production line as they are unable to comply with emission standards. For those still in use, the EPA has been offering subsidies since 2008 as an incentive to replace the old vehicles. More heavy-handed measures have been required in Kaohsiung City and Taipei City where air quality purification zones have been locally delineated based on the actual state of pollution. The riding of two-stroke motorcycles will be restricted or banned in designated areas after the set deadlines. From 2008, the EPA has been providing subsidies to phase out two-stroke motorcycles, and on 20 July 2015 promulgated the Regulations Governing Subsidies for Scrapping Two-stroke Motorcycles and Purchasing New Two-wheeled Electric Vehicles. The regulations increased subsidies and requested local governments to tack on additional subsidies to increase incentives for citizens to scrap their two-stroke motorcycles more quickly. As of the end of 2015, subsidies had been given to retire over 770,000 two-stroke motorcycles, with 120,000 being retired in 2015 alone. The number of registered light motorcycles, mostly two-stroke ones, has dropped from an all-time high of 4.6 million in 2003 to 1.88 million in 2015, a decrease of nearly 2.72 million vehicles in a period of 12 years.