ABSTRACT
The Commonwealth has power to legislate with respect to trade and commerce among the States under s 51(i) of the Constitution, but this power can only be used subject to the restriction of s 9250 which provides that trade and commerce between the States shall be absolutely free. The phrase trade and commerce including the business of carrying goods and passengers for reward means that although the Commonwealth can regulate interstate transport it cannot restrict or prevent it. The requirement of interstate road traffic to pay more than a reasonable sum for the uses of roads infringes s 92.51 The balance between reasonable regulation and prohibition of interstate trade has been extensively explored by the courts as has the issue of what constitutes part of interstate road transport.52
