premise: For this analysis, the baseline scenarios for 2010 and 2020 assume no additional emissions control regulation beyond the continuing effects of Title IV of the Clean Air Act Amendments, the NOx SIP Call, and other promulgated federal rules issued under the Clean Air Act.
hypothesis: The baseline scenarios for 2010 and 2020 assume no extensive emissions control regulations, but do not account for the NOx SIP Call and other rules that affect car emissions. 