Private Activity Bonds (PABs) are debt instruments authorized by the Secretary of Transportation and issued by a conduit issuer on behalf of a private entity for highway and freight transfer projects, allowing a private project sponsor to benefit from the lower financing costs of tax-exempt municipal bonds. Section 11143 of Title XI of SAFETEA-LU amended Section 142(a) of the Internal Revenue Code to add highway and freight transfer facilities to the types of privately developed and operated projects for which PABs may be issued. This change allows private activity on these types of projects while maintaining the tax-exempt status of the bonds. The law limits the total amount of such bonds to $15 billion and directs the Secretary of Transportation to allocate this amount among qualified facilities. Passage of the private activity bond legislation reflects the Federal Government's desire to increase private sector investment in U.S. transportation infrastructure.