absolute blocking
nounUS /ˈæb.səˌlut ˈblɑk.ɪŋ/
1
A system of managing trains that breaks the line into small segments, and if a train is in a segment, no other train may follow, unless the second train is following the first, with caution.
Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.