Overview

• The 2019 legislation doubled Illinois’s base motor fuel tax and mandated annual CPI-linked hikes each July 1.
• For fiscal year 2026, the gasoline tax rises by 1.3 cents to $0.483 per gallon and diesel climbs to $0.558 per gallon.
• CPI-based increases add roughly $6 in annual fuel costs for the average driver, equating to about 18 cents more per gallon for a 14-gallon fill-up.
• Under the constitutional Transportation Taxes and Fees Lockbox Amendment, 80% of new revenue funds state highways and 20% supports local transit and infrastructure.
• Including federal and local levies, Illinois now has the second-highest fuel tax rate in the nation, trailing only California.