N.J. Stat. Ann. § 32:1-90

The construction, maintenance and operation of said bridge is in all respects for the benefit of the people of the two states, for the increase of their commerce and prosperity, and for the improvement of their health and living conditions, and the port authority shall be regarded as performing a governmental function in undertaking the said construction, maintenance and operation and in carrying out the provisions of law relating to the said bridge and shall be required to pay no taxes or assessments upon any of the property acquired by it for the construction, operation and maintenance of such bridge.