"Early Adventures in Constitutionalism"
The high-speed rail debate of the early 19th century concerned canal construction, and in 1817 James Madison vetoed a canal bill, explaining that it’s unconstitutional for the federal government to spend money on transportation infrastructure:
The legislative powers vested in Congress are specified and enumerated in the eighth section of the first article of the Constitution, and it does not appear that the power proposed to be exercised by the bill is among the enumerated powers, or that it falls by any just interpretation with the power to make laws necessary and proper for carrying into execution those or other powers vested by the Constitution in the Government of the United States.
“The power to regulate commerce among the several States” can not include a power to construct roads and canals, and to improve the navigation of water courses in order to facilitate, promote, and secure such commerce without a latitude of construction departing from the ordinary import of the terms strengthened by the known inconveniences which doubtless led to the grant of this remedial power to Congress.
I would have said that the power “[t]o establish Post Offices and Post Roads” implies a generic grant of authority to do transportation.