N.Y. Bridges & Tunnels New York-New Jersey Law § 12
The two said states covenant and agree with each other and with the holders of any bonds or other securities or obligations of the port authority, issued or incurred for bridge or tunnel purposes and as security for which there may or shall be pledged the tolls and revenues or any part thereof of any vehicular bridge or tunnel (including the said Holland tunnel and the said Midtown Hudson tunnel), that the two said states will not, so long as any of such bonds or other obligations remain outstanding and unpaid, diminish or impair the power of the port authority to establish, levy and collect tolls and other charges in connection therewith; and that the two said states will not, so long as any of such bonds or other obligations remain outstanding and unpaid, authorize the construction of any vehicular bridges or tunnels over or under interstate waters as herein defined within the said port of New York district, by any person or body other than the port authority, in competition with those whose tolls or other revenues are pledged as aforesaid; provided that nothing herein contained shall be deemed to refer to the bridge authorized by the act of congress of July eleven, eighteen hundred ninety, chapter six hundred and sixty-nine, and acts amendatory thereof and supplemental thereto; and provided further that nothing herein contained shall preclude the authorization of the construction of such competitive tunnels or bridges by other persons or bodies if and when adequate provision shall be made by law for the protection of those advancing money upon such obligations.
N.Y. Bridges and Tunnels New York-New Jersey Law § 12