ASCT is standard practice (and has been standard practice) on most junctions in most towns and cities in the UK for over 20 years.
In the USA, a significant amount of tax-funded infrastructure is actually built out by contractors, which means there's profit going to a corporation, and there's often a cynical idea that the contracts go out to whoever will send a kickback in the form of a campaign contribution to whoever makes the decision on which contractor to use.
That means all the bribery has to be firmly under the table instead, rather than legalized.