The seemingly endless studying of what ails the Interstate 70 corridor between Denver and Colorado’s mountain resort communities has started feeling a bit like the snarled driving nightmare common on mid-winter Sunday afternoons. The process inches forward at a glacial rate as the traffic just keeps building. But state and federal regulators seem buoyed by achieving at least one milestone on Thursday, as the Federal Highway Administration (FHWA) signed a Record of Decision (ROD) for the Interstate 70 Programmatic Environmental Impact Statement (PEIS).