English.chinabuses.com: According to a new forecast presented by R.L. Polk & Company, a leading auto industry market research firm, reports that the number of hybrid auto sales will double in the next three years.

R.L. Polk establishes future rates of growth based on past hybrid vehicle registrations—the company has unique access to owner registration data. Polk also analyzes consumer confidence in the overall auto market and product availability. According to announcements from global automakers, the number of hybrids is expected to grow from about 20 today to more than 40 by the end of 2010.