Time.com has an interesting article on ’boutique gas’. Starting in the ’90s state and federal rules have mandated certain environmental regulations on gas sold only in specific regions or metropolitan areas. This reduces the competitiveness of the gas market by breaking the national market into many smaller markets that each have their own barriers to entry.
In a truly national gasoline market, refiners would be under far more price pressure from competitors than they are under the current setup.
Unified standards on gasoline would increase competition and lower prices without price controls or shortages. If Congress wants lower gas prices they should get rid of these barriers to fair market competition.