SACRAMENTO, CA — Speaking on an air quality panel at a conference in California, a California Air Resources Board (CARB) member said that incentive-based program may not be working adequately, and stronger efforts may be needed to reduce emissions from existing fleets, according to Weststart/CALSTART. CARB board member DeeDee D'Adamo said that the existing diesel fleet is simply turning over too slowly despite generous incentive programs. D'Adamo said, "We need to start looking at other strategies" to reduce emissions from heavy-duty vehicles, particularly in the San Joaquin Valley in California. She suggested that engine retrofits and emission control technologies could be adapted to existing fleets to significantly reduce air pollution. D'Adamo made her comments at a conference in Sacramento, Calif., hosted by the Great Valley Center.