The EPA stated that according to statistics, mobile pollution sources account for 30~37% of Taiwan’s PM2.5 emissions. Among that, 2~2.6% of emissions come from two-stroke motorcycles, and 11.2~16.8% from heavy-duty diesel trucks, showing the need to speed up the phase-out of said vehicles. Starting in 2008, the EPA has been offering subsidies for phasing out two-stroke motorcycles. From 2010, the EPA has further subsidized the purchase of electric motorcycles. In addition, the governments of Taipei City, Taoyuan City, Taichung City, Kaohsiung City, Yilan County and Nantou County provide additional subsidies of NT$4000-30,000 to mid- and low-income households to replace two-stroke motorcycles with new electric ones.

In addition, since August 2017 the EPA has offered subsidies for phasing out heavy-duty diesel trucks subject to the first and second phase vehicle emission standards. Data shows that the phase-out of more than 1.32 million two-stroke motorcycles and more than 6,000 of the said diesel trucks has been subsidized as of the end of March 2018. A goal has been set to phase out all the two-stroke motorcycles and heavy-duty diesel trucks targeted by the phase 1 and 2 vehicle emission standards by the end of 2019.

Besides the subsidies above, the Legislative Yuan has passed the preliminary review of the draft amendments to the Air Pollution Control Act formulated by the EPA. Article 36 in the revision authorizes the EPA to tighten the original emission standards for motor vehicles that have been manufactured over ten years ago. Article 40 mandates that competent authorities at all levels may designate air pollution control zones for mobile source pollution control according to local air quality and pollution characteristics.

Once the amendments are approved, the EPA estimates that they will affect 98,000 gasoline vehicles manufactured before 1991, as well as 530,000 diesel vehicles and more than 7 million motorcycles regulated by the phase 1-4 vehicle emission standards. Taking two-stroke motorcycles for instance, stricter emission standards for vehicles manufactured more than ten years ago would lead to an increase of failed tests for CO emissions, rising from 14% to 45%, and an increase of failed tests for hydrocarbon emissions from 6.5% to 9.5%. Other than replacing two-stroke motorcycles faster, vehicle owners will also consequently be encouraged to properly maintain their vehicles in order to comply with the new standards. A two-year grace period will be in place before the new standards take effect.

The EPA pointed out that although competent authorities at all levels are authorized to designate air quality zones to limit or ban the entrance of certain vehicles, the zone area and the targeted vehicles must be deemed necessary. The control zones will not cover the entire country, and a grace period of three to Although the subsidy provides an incentive for phasing out old vehicles, it is not mandatory. The EPA is considering amending related regulations to put old, highly polluting vehicles under control in order to hasten the phase-out of such vehicles. Owners are encouraged to get rid of their old vehicles soon, so as to not only be eligible to apply for a subsidy, but also to avoid the trouble of violating future emission standards and being limited from driving in certain areas.