SPRINGFIELD, Ill. — Most gas stations make more money on a $2 bag of ice than on a $3.55 gallon of gas. A tax increase, station owners say, would kill their businesses.

A group of business leaders and labor unions, the Transportation for Illinois Coalition, wants lawmakers to raise one of Illinois’ two gas taxes — the per-gallon tax — by 4 cents a gallon to help pay for $1.8 billion in new roads and bridges.

Carl Adams is president of the Illinois Ayers Oil Co., which runs gas stations along Illinois’ western border. Station owners — and drivers — in Illinois can’t stand another tax, he said.