The commission of the state of New Jersey appointed pursuant to section 32:9-1 of this title may provide for the construction and maintenance of free bridges across the Delaware river between this state and the commonwealth of Pennsylvania, and for that purpose may act in conjunction with a similar commission appointed for that purpose by the commonwealth of Pennsylvania, which commission of the commonwealth of Pennsylvania and of the state of New Jersey shall be known as the “joint commission” of such two states, whenever referred to in this chapter.