Federal highways were created for the national defense, so that military vehicles and personnel could be moved quickly. Is that a constitutional violation in your eyes?
Pollution, especially air and water pollution can cross state borders easily. Do you believe that all instances of such pollution must be tried in lawsuits between states by the Supreme Court?
Interstate package delivery. Such packages can contain illegal, dangerous and harmful products, and can be used to facilitate wire fraud. Cargoes of contaminated plants and animals can spread disease throughout the US. If under state jurisdiction, packages can be inspected and taxed by each state it passes through.
Pollution... Now you are going to make Leftist EPA arguments as well? Whatever happened to having damages to you or your property being arbitrated via the courts? Oh... That's right, there's no money in it for the lawyers if a criminal damage complaint were in the offing instead of a mere civil suit. Nor is there as much power to be had for yet another government agency with no real reason to exist other than to expand its mandate. Technology in a free market has made things "cleaner" than ANY government mandate ever has.
Interstate package delivery.
Now you are going really far afield in your quest to uphold your favored leviathan FedGov. Dangerous? Like bullets? I order most of my components for reloading online from other States. Are you saying the FedGov has a legit interest there?
You are on the wrong forum...