Map of the US National Highway System
Does a state, city or municipality have a the legal right to use a Federal highway for speed or red light cameras? If yes does the federal government share in the revenue generated from the cameras? What permits or permissions from what federal agencies are required?
Despite the Interstate or US highway label it is probably owned by the state or city and not the Federal government. In order to use the cameras the State legislature would have to enact legislation describing how and where photo enforcement could be used. Only rarely do these roads typically belong to the federal government and these roads are on military sites, national parks and perhaps Indian reservations.