California Air Resources Board

Please see detailed feedback attached.

As a brief summary, I believe the roadmap has many key strengths, is compelling, and merits the resources to achieve its mission. Four areas where it could be further strengthened are as follows. First, it will more effective if it includes a commitment to use and *track* metrics on risk/disparity. Second, consider using the now-widely adopted disparity metrics that were developed under CARB/OEHHA funding. Third, ensure that the problem is quantified and managed at the scale that matters, which includes sharp within-urban gradients in exposure and risk. Fourth, integrate measurements, models, and inventories into a unified, coherent and multi-scale data strategies, taking advantage of the complementary strengths of all approaches.