Outgoing Chicago Mayor Rahm Emanuel says the state's motor-fuel tax should be increased to fund highway and bridge improvements. The Democrat and colleagues from the Metropolitan Mayors Caucus said Tuesday the 19-cents-per-gallon tax should be increased by as much as 30 cents . The caucus represents 275 municipal governments in Chicago and its suburbs. Illinois Transportation Secretary Randy Blankenhorn called last week for an increase too. Republican Gov. Bruce Rauner's cabinet members says three-fourths of the state's bridges are in need of repair .