Over the past decade the air quality in Texas' two largest cities, Houston and Dallas, has improved significantly with few air quality exceedance days and lower peak pollution levels. However, both metropolitan regions are still in non-compliance with the EPA 8-hr ozone standard. Recent air quality field studies in Houston (2006 and 2009), and Dallas/Fort Worth (2011) have revealed surprising levels of photochemical radical precursors including formaldehyde, nitrous acid, nitrylchloride, and hydrochloric acid. Photochemical modeling simulations have done a good job of recreating select urban ozone events but appear to fall short in correctly capturing boundary layer dynamics and the heterogeneous chemical reactions to correctly model OH radical precursors. Focused studies on combustion devices such as petrochemical process flares and natural gas compressor stations suggest that the emissions of radical precursors are significantly underestimated in the emission inventories. Recent measurement advances in halogen chemistry, heterogenous chemistry, boundary layer dynamics, and radical precursor levels need to be incorporated into three dimensional chemical transport models to correctly forecast air quality events in urban atmospheric environments.