§ 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.