The E-Road network is not a system of electric routes as it might seem at first glance, but rather the international route network crisscrossing all of Europe and even well into Asia. Now, it has been known new routes are being added in the USA and Canada, as they are the only members of the UNECE without E-roads (another thing is why they are in the United Nations Economic Comission for
Europe, but that is another topic).
It is already known Canada will finally have an (inter)nationally numbered road network as E-routes are set to replace the provincial roads and not just overlay them, but it is not sure how (and if) they will be signposted in the USA, as there already the Interstates and US Routes. Another thing is the numbering, the East-West A class roads are easy, just make even numbers cross the Atlantic (and they can be expanded up to E128 if needed, much like the Easternmost North-South route is E127), but the North-South A class roads will need a real headscratcher as both the USA and Canada are (way) West of E01 in Ireland and the Iberian Peninsula, maybe they could introduce negative numbers, which would also help with B class roads (they had to add a trailing zero for the Caucasus and Central Asia). This is something that has been left out for the time being, it will be discussed at a further meeting.
Anyway,
here is a recording of the recent meeting between the UNECE, the FHWA, AASHTO, and Transport Canada. Any thoughts?