The poster said “warheads carried around”...not deployed. DOE/NNSA/OST is charged with safeguarding special material from Air/Naval Bases and transport by VERY HEAVILY armed 18 wheelers and support vehicles. Usually going to/from Pantex Plant in TX for repair/dismantlement.
The SST’s also transport the devices between operational bases and the stockpile sites, as you know, but most on this site do not.