The block section KH_ST_20 must be handled differently depending on the
operation direction of a train passing through. If KH_ST_10 is operated in
clockwise direction and a train runs from ICKH_LN to KH_ST_9, this train is
not allowed to stop within KH_ST_20 and the velocity meter M2 doesn't need to
be used.
If KH_ST_20 is operated in counterclockwise direction, a train running from
KH_ST_9 to OC_JCT is allowed to stop in front of signal OC_JCT_S2. Here,
the velocity meters are needed to control the speed of a train approaching
the signal OC_JCT_S2.