TY  JOUR
TI  Signals and interlocking development during imperialism (1906-1917). Part 4: Safety devices
KW  safety of operation
KW  color light signal
KW  key interlocking
KW  trafﬁc hazard
KW  fatal crash
JO  Transport automation research
AU  Lupal, N..
PY  2017
IS  3
PB  FSBEI HE &quot;Emperor Alexander I St. Petersburg State Transport University&quot;