Illinois state Sen. Dave Syverson, R-Rockford, joins state Rep. Dan Brady, R-Bloomington, in supporting an increase in the state’s gas tax.

Illinoisans already pay some of the highest taxes in the nation, including high taxes at the pump.

Illinois drivers pay, on average, $0.39 per gallon in state gas taxes. That amount adds up quickly. A driver purchasing 15 gallons of gas in Illinois shells out about $6 extra in state taxes, on top of the price of the gasoline itself. Illinois’ per-gallon gas tax is the eighth highest in the country, according...