CARB survey letter
Just got a quick reply from Mr. Jiao.
We're from the CARB's on-road emission inventory modeling group and working on refining the California Emission Factor model (EMFAC) characterization for age 45+ vehicle emissions and activities. Because of data limitation, our current model assumes that age 45+ vehicles drive on an average of 3000 miles a year. But we doubt this annual mileage number and would like to collect some first-hand information regarding vehicle usage and storage (relates to evaporative emissions estimation). The results of the survey will be used in research purpose only to update the model, and will not affect your vehicle registration/smog status at all.
Regards,
Wan