SAFETEA-LU also made available to equity investors in highways and intermodal facilities tax-exempt financing that had long been a staple of private airport, transit, water and wastewater projects. Previously highway and projects were eligible for tax-exempt financing only if there was no significant revenue sharing, no private equity and no long term operating contracts. Thus federal income tax laws effectively precluded a project from combining tax-exempt financing and concession-type PPPs. The lower interest cost of the $15 billion in private activity bonds to be allocated by the Secretary of Transportation will help make economically feasible Title 23 funded projects that would otherwise prove infeasible with higher cost taxable debt.