In addition to other programs authorized in this article, a district may, on or after March 1, 1993, establish programs to identify gross polluters and other high-emitting vehicles whose emissions could be reduced by repair, using remote sensors or other methods, and to provide financial incentives to encourage the repair or scrapping of these vehicles as a method of reducing mobile source emissions for the purposes of Section 40914. The programs authorized by this section are not intended to impose additional emission reduction requirements, but instead are intended to provide more cost-effective alternative methods to meet existing requirements.